Re: [Qgis-user] Fw: Did scale change outputting to PDF?
John, Is it possible to ask Kinkos what scale they printed the base maps? They don't have to actually reprint the maps, just go through the motions. Open the PDF and look at the print options. As Andreas points out, the default is often "Fit" and there will be a "zoom" or "scale" percent displayed in the application (I use Foxit, and Adobe and both show this). The page size parcel maps will have to be printed at this scale. If they can guarantee that the print scale was 100%, then I would assume some other export discrepancy. David On 5/27/2021 4:15 AM, Andreas Neumann wrote: Hi John, No - the PDF export does not distort the scale. But the printing of the PDF file might. It is absolutely important that - when printing the PDF - the setting "Actual size" or "Custom Scale at 100%" is used. All other options will change the scale. As far as I know, the default option when printing is "Fit", which will often shrink the content by some percentage - because some often "invisible" or white background might be present in the file that extends right to the edge of the page format. Acrobat then thinks that the content goes beyond the "printable area" of the printer and will scale down the whole file. Hope that clarifies this potential pit-fall when printing PDF files. It might well be a different issue than the one I describe, but this is a very common source of error that I know. Andreas On 2021-05-27 10:02, John Antkowiak wrote: Hi, Jochen. Your suggestion sounds do-able; I'll play around with it and see if I can sort it out. I've got some digital calipers around here somewhere :) What I'm hearing is that the process of converting both the base map (and yes, I did create it in QGIS) and the parcel maps into PDF will distort the scale. (And that a print shop might compound the problem by manually fitting the source file to the printable area. Yes?) A question then is why didn't the PDF conversion distort them all the same way, to the same degree? The base maps are done now and I couldn't afford to do them again no matter what, so they are what they are. Going forward, is there an export option in Print Layout that will not distort the scale of the parcel maps? I am so relieved that someone has an explanation for this! - John A. - Forwarded Message - *From:* j.hu...@post-ist-da.de *To:* "qgis-user@lists.osgeo.org" *Sent:* Thursday, May 27, 2021, 03:33:12 AM EDT *Subject:* Re: [Qgis-user] Did scale change outputting to PDF? Hi John, as I understand it, you created the base map in QGIS. If you use the measure tool in QGIS to get the distance between two distinct features in the map (e.g. road intersections) and then measure the same distance on the printed base map with a ruler, it should be possible to calculate the scale. Maybe use two distances, one aligned more or less horizontally and one vertically, to check if the scaling is proportional. As Andreas pointed out, it is probably a problem with the settings when the PDF was printed. In my experience it is a good idea to go to print shops usually working for architects and engineers since they are familiar with the importance of scaling (for advertising etc. it is more important that the whole content is printed, so that scaling might be used to fit the output to the printable area without potential cropping). You can print directly to a plotter in QGIS if you have access to the device, avoiding the PDF detour. EPSG 2264 should be fine. Units should be US feet. Regards Jochen Am 27.05.21 um 07:15 schrieb John Antkowiak: Hi. This plan was too simple to fail - but it failed. The charity whose project this is needed a large (that is... massive) paper wall map on which to plot and rethink its delivery driver assignments. Both drivers and delivery addresses are subject to change from week to week but it's not a pizza delivery; this is a regular run to supply people in a bad way. So the plan was to print the base map (roads and road names and county boundaries only) and then print 8.5 x 11 address maps with parcel data and orthos. That way, the base maps don't change but the physical parcel layer is flexible. (On top of that is a third paper layer indicating which drivers go where so someone can stand back and take in the whole picture graphically. Not a cutting-edge state of the digital art solution, but not everyone is cut out for that. It is what it is.) In order for this to work, the parcel maps have to be the same scale as the base map. Which they were... in QGIS. We have to convert all the maps to PDF to print them, and we had to send the base map PDFs to FedEx/Kinkos to print the 9 map grid panels at 42" by 62" each. When we got the big base maps up on the wall, we discovered the scale did not match the 8.5" x 11" parcel maps output to PDF and printed from home. It's not off by a lot, but it's enough to be painfully obvious from a single standard size sheet of paper. I d
Re: [Qgis-user] Fw: Did scale change outputting to PDF?
John Antkowiak writes: > When I measure the distance in QGIS, I'm given the choice to use the > Ellipsoidal method or the Cartesian method, which yield different > distances. Which one of those two choices is my wooden ruler using? For a state plane coordinate system, I would expect the distances from the two methods to be quite close. As a wild guess without really looking it up, within 0.5%. That's part of the point of how SPCs are designed. Presumably the "Project CRS" is the state plane one, and thus the scale relates distances in that (projected, sometimes called Cartesian) CRS to distances on the paper.To have matching maps, you should have both of them produced with the same project CRS. (I have no idea if qgis will allow a map view CRS that is different from project CRS but even if so my advice would be not to go there because you are already in over your head.) signature.asc Description: PGP signature ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] Fw: Did scale change outputting to PDF?
So...h. When I measure the distance in QGIS, I'm given the choice to use the Ellipsoidal method or the Cartesian method, which yield different distances. Which one of those two choices is my wooden ruler using? Because if they're not the same, the resulting scale isn't going to match... Seems like this shouldn't be this difficult lol... - John A. - Forwarded Message - From: "j.hu...@post-ist-da.de" To: "qgis-user@lists.osgeo.org" Sent: Thursday, May 27, 2021, 03:33:12 AM EDTSubject: Re: [Qgis-user] Did scale change outputting to PDF? Hi John, as I understand it, you created the base map in QGIS. If you use the measure tool in QGIS to get the distance between two distinct features in the map (e.g. road intersections) and then measure the same distance on the printed base map with a ruler, it should be possible to calculate the scale. Maybe use two distances, one aligned more or less horizontally and one vertically, to check if the scaling is proportional. As Andreas pointed out, it is probably a problem with the settings when the PDF was printed. In my experience it is a good idea to go to print shops usually working for architects and engineers since they are familiar with the importance of scaling (for advertising etc. it is more important that the whole content is printed, so that scaling might be used to fit the output to the printable area without potential cropping). You can print directly to a plotter in QGIS if you have access to the device, avoiding the PDF detour. EPSG 2264 should be fine. Units should be US feet. Regards Jochen Am 27.05.21 um 07:15 schrieb John Antkowiak: Hi. This plan was too simple to fail - but it failed. The charity whose project this is needed a large (that is... massive) paper wall map on which to plot and rethink its delivery driver assignments. Both drivers and delivery addresses are subject to change from week to week but it's not a pizza delivery; this is a regular run to supply people in a bad way. So the plan was to print the base map (roads and road names and county boundaries only) and then print 8.5 x 11 address maps with parcel data and orthos. That way, the base maps don't change but the physical parcel layer is flexible. (On top of that is a third paper layer indicating which drivers go where so someone can stand back and take in the whole picture graphically. Not a cutting-edge state of the digital art solution, but not everyone is cut out for that. It is what it is.) In order for this to work, the parcel maps have to be the same scale as the base map. Which they were... in QGIS. We have to convert all the maps to PDF to print them, and we had to send the base map PDFs to FedEx/Kinkos to print the 9 map grid panels at 42" by 62" each. When we got the big base maps up on the wall, we discovered the scale did not match the 8.5" x 11" parcel maps output to PDF and printed from home. It's not off by a lot, but it's enough to be painfully obvious from a single standard size sheet of paper. I don't know how to reverse engineer the big map scale precisely enough to enter a new scale number in the QGIS Print Layout. I didn't foresee it because this never would've been a conceivable scenario at the engineering firm where I picked up my meager GIS skills. (ArcMap sent a map directly to the plotter without interim steps.) There was no scale bar on the map. It shouldn't have been needed for this. Did something happen to the map scale when QGIS output the map to PDF? Could the size of the image on the pdf page have been adjusted manually or otherwise when being sent to a plotter with 42" paper? Could the image have been distorted horizontally differently from vertically? For the life of me, I cannot trial-and-error guess at a scale to enter. I've gone through dozens of new 8.5" x 11" test maps trying to guess the correct scale. Any ideas? Thank you all - John A. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] Fw: Did scale change outputting to PDF?
Hi, Jochen. Your suggestion sounds do-able; I'll play around with it and see if I can sort it out. I've got some digital calipers around here somewhere :) What I'm hearing is that the process of converting both the base map (and yes, I did create it in QGIS) and the parcel maps into PDF will distort the scale. (And that a print shop might compound the problem by manually fitting the source file to the printable area. Yes?) A question then is why didn't the PDF conversion distort them all the same way, to the same degree? The base maps are done now and I couldn't afford to do them again no matter what, so they are what they are. Going forward, is there an export option in Print Layout that will not distort the scale of the parcel maps? I am so relieved that someone has an explanation for this! - John A. - Forwarded Message - From: j.hu...@post-ist-da.de To: "qgis-user@lists.osgeo.org" Sent: Thursday, May 27, 2021, 03:33:12 AM EDTSubject: Re: [Qgis-user] Did scale change outputting to PDF? Hi John, as I understand it, you created the base map in QGIS. If you use the measure tool in QGIS to get the distance between two distinct features in the map (e.g. road intersections) and then measure the same distance on the printed base map with a ruler, it should be possible to calculate the scale. Maybe use two distances, one aligned more or less horizontally and one vertically, to check if the scaling is proportional. As Andreas pointed out, it is probably a problem with the settings when the PDF was printed. In my experience it is a good idea to go to print shops usually working for architects and engineers since they are familiar with the importance of scaling (for advertising etc. it is more important that the whole content is printed, so that scaling might be used to fit the output to the printable area without potential cropping). You can print directly to a plotter in QGIS if you have access to the device, avoiding the PDF detour. EPSG 2264 should be fine. Units should be US feet. Regards Jochen Am 27.05.21 um 07:15 schrieb John Antkowiak: Hi. This plan was too simple to fail - but it failed. The charity whose project this is needed a large (that is... massive) paper wall map on which to plot and rethink its delivery driver assignments. Both drivers and delivery addresses are subject to change from week to week but it's not a pizza delivery; this is a regular run to supply people in a bad way. So the plan was to print the base map (roads and road names and county boundaries only) and then print 8.5 x 11 address maps with parcel data and orthos. That way, the base maps don't change but the physical parcel layer is flexible. (On top of that is a third paper layer indicating which drivers go where so someone can stand back and take in the whole picture graphically. Not a cutting-edge state of the digital art solution, but not everyone is cut out for that. It is what it is.) In order for this to work, the parcel maps have to be the same scale as the base map. Which they were... in QGIS. We have to convert all the maps to PDF to print them, and we had to send the base map PDFs to FedEx/Kinkos to print the 9 map grid panels at 42" by 62" each. When we got the big base maps up on the wall, we discovered the scale did not match the 8.5" x 11" parcel maps output to PDF and printed from home. It's not off by a lot, but it's enough to be painfully obvious from a single standard size sheet of paper. I don't know how to reverse engineer the big map scale precisely enough to enter a new scale number in the QGIS Print Layout. I didn't foresee it because this never would've been a conceivable scenario at the engineering firm where I picked up my meager GIS skills. (ArcMap sent a map directly to the plotter without interim steps.) There was no scale bar on the map. It shouldn't have been needed for this. Did something happen to the map scale when QGIS output the map to PDF? Could the size of the image on the pdf page have been adjusted manually or otherwise when being sent to a plotter with 42" paper? Could the image have been distorted horizontally differently from vertically? For the life of me, I cannot trial-and-error guess at a scale to enter. I've gone through dozens of new 8.5" x 11" test maps trying to guess the correct scale. Any ideas? Thank you all - John A. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org
[Qgis-user] Fw: Did scale change outputting to PDF?
Hi, Andreas. I'm not entirely conversant in the CRS. I do understand the basics. All layers use the same CRS, NAD83 / North Carolina (ftUS), EPSG:2264. I know that the NAD variant is State Plane but I'm not familiar with EPSG. - John A. - Forwarded Message - From: Andreas Neumann To: John Antkowiak Cc: QGIS User List Sent: Thursday, May 27, 2021, 02:43:34 AM EDTSubject: Re: [Qgis-user] Did scale change outputting to PDF? Hi again John, Another thing: what projection (CRS) did you use? Not all CRS are suitable for printing to scale - esp. the Web Mercator projections are often not suitable. Greetings, ANdreas On 2021-05-27 08:20, Andreas Neumann wrote: Hi John, A very common error when printing PDF maps (regardless of the software that generated the PDF), is that the print shop scales it down to fit the "printable" area. Then you end up at somewhere around 95% (plus / minus) a bit The PDF viewers (at least the Acrobat one) has a setting to print at 100% (but this is not the default) - it has to be done consciously. However, this normally scales uniformly, not separately for width and height. On the topic of "base maps": Can you explain what source/mechanism for "base maps" you used? Are you refering to "tiled" maps, perhaps consumed through the OpenLayers plugin? This plugin is a known to be a source of error for misalignments and the plugin should be avoided. Even if you didn't use this plugin, I have to say that tiled base maps (e.g. consumed by the quick map services plugin or otherwise) are usually not suited for printing as their resolution is optimized for screen viewing. Printing these tiles would result in disappointing quality. Greetings, Andreas On 2021-05-27 07:15, John Antkowiak wrote: Hi. This plan was too simple to fail - but it failed. The charity whose project this is needed a large (that is... massive) paper wall map on which to plot and rethink its delivery driver assignments. Both drivers and delivery addresses are subject to change from week to week but it's not a pizza delivery; this is a regular run to supply people in a bad way. So the plan was to print the base map (roads and road names and county boundaries only) and then print 8.5 x 11 address maps with parcel data and orthos. That way, the base maps don't change but the physical parcel layer is flexible. (On top of that is a third paper layer indicating which drivers go where so someone can stand back and take in the whole picture graphically. Not a cutting-edge state of the digital art solution, but not everyone is cut out for that. It is what it is.) In order for this to work, the parcel maps have to be the same scale as the base map. Which they were... in QGIS. We have to convert all the maps to PDF to print them, and we had to send the base map PDFs to FedEx/Kinkos to print the 9 map grid panels at 42" by 62" each. When we got the big base maps up on the wall, we discovered the scale did not match the 8.5" x 11" parcel maps output to PDF and printed from home. It's not off by a lot, but it's enough to be painfully obvious from a single standard size sheet of paper. I don't know how to reverse engineer the big map scale precisely enough to enter a new scale number in the QGIS Print Layout. I didn't foresee it because this never would've been a conceivable scenario at the engineering firm where I picked up my meager GIS skills. (ArcMap sent a map directly to the plotter without interim steps.) There was no scale bar on the map. It shouldn't have been needed for this. Did something happen to the map scale when QGIS output the map to PDF? Could the size of the image on the pdf page have been adjusted manually or otherwise when being sent to a plotter with 42" paper? Could the image have been distorted horizontally differently from vertically? For the life of me, I cannot trial-and-error guess at a scale to enter. I've gone through dozens of new 8.5" x 11" test maps trying to guess the correct scale. Any ideas? Thank you all - John A. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] Fw: Did scale change outputting to PDF?
Thank you, Andreas - I thought there must be a PDF error. I didn't use any tiling plugin but rather created my own polygon for that. Other than the scale issue, I'm very pleased with the print quality. So if the scale error is proportional I should be able to eventually home in on the correct scale to use. That's promising, and I appreciate your letting me know. Thank you very much! - John A. - Forwarded Message - From: Andreas Neumann To: John Antkowiak Cc: QGIS User List Sent: Thursday, May 27, 2021, 02:27:20 AM EDTSubject: Re: [Qgis-user] Did scale change outputting to PDF? Hi John, A very common error when printing PDF maps (regardless of the software that generated the PDF), is that the print shop scales it down to fit the "printable" area. Then you end up at somewhere around 95% (plus / minus) a bit The PDF viewers (at least the Acrobat one) has a setting to print at 100% (but this is not the default) - it has to be done consciously. However, this normally scales uniformly, not separately for width and height. On the topic of "base maps": Can you explain what source/mechanism for "base maps" you used? Are you refering to "tiled" maps, perhaps consumed through the OpenLayers plugin? This plugin is a known to be a source of error for misalignments and the plugin should be avoided. Even if you didn't use this plugin, I have to say that tiled base maps (e.g. consumed by the quick map services plugin or otherwise) are usually not suited for printing as their resolution is optimized for screen viewing. Printing these tiles would result in disappointing quality. Greetings, Andreas On 2021-05-27 07:15, John Antkowiak wrote: Hi. This plan was too simple to fail - but it failed. The charity whose project this is needed a large (that is... massive) paper wall map on which to plot and rethink its delivery driver assignments. Both drivers and delivery addresses are subject to change from week to week but it's not a pizza delivery; this is a regular run to supply people in a bad way. So the plan was to print the base map (roads and road names and county boundaries only) and then print 8.5 x 11 address maps with parcel data and orthos. That way, the base maps don't change but the physical parcel layer is flexible. (On top of that is a third paper layer indicating which drivers go where so someone can stand back and take in the whole picture graphically. Not a cutting-edge state of the digital art solution, but not everyone is cut out for that. It is what it is.) In order for this to work, the parcel maps have to be the same scale as the base map. Which they were... in QGIS. We have to convert all the maps to PDF to print them, and we had to send the base map PDFs to FedEx/Kinkos to print the 9 map grid panels at 42" by 62" each. When we got the big base maps up on the wall, we discovered the scale did not match the 8.5" x 11" parcel maps output to PDF and printed from home. It's not off by a lot, but it's enough to be painfully obvious from a single standard size sheet of paper. I don't know how to reverse engineer the big map scale precisely enough to enter a new scale number in the QGIS Print Layout. I didn't foresee it because this never would've been a conceivable scenario at the engineering firm where I picked up my meager GIS skills. (ArcMap sent a map directly to the plotter without interim steps.) There was no scale bar on the map. It shouldn't have been needed for this. Did something happen to the map scale when QGIS output the map to PDF? Could the size of the image on the pdf page have been adjusted manually or otherwise when being sent to a plotter with 42" paper? Could the image have been distorted horizontally differently from vertically? For the life of me, I cannot trial-and-error guess at a scale to enter. I've gone through dozens of new 8.5" x 11" test maps trying to guess the correct scale. Any ideas? Thank you all - John A. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Fw: Did scale change outputting to PDF?
Hi John, Another source of error is that you accidentally change the map scale during exporting the PDF map sheets in QGIS. Did you generate the PDF in the main QGIS window or in the "Menu Project --> Import/Export --> Export map to PDF" or by making a print layout in the separate print layout window and then exporting from there? I strongly recommend the latter approach. Also, when you generate a series of PDFs with the same scale and different extend, you should preferably use the Atlas print functionality - maybe you did that anyway. Not knowing more about the process, I can see several stages in the process where the map scale may accidentally change. Also - you may already know this - but to state the obvious: the map scale in the main QGIS windows is not tightly linked to the map scale of the print layout window. They are independent. Hope this all helps a bit and makes sense? Andreas On 2021-05-27 10:15, Andreas Neumann wrote: Hi John, No - the PDF export does not distort the scale. But the printing of the PDF file might. It is absolutely important that - when printing the PDF - the setting "Actual size" or "Custom Scale at 100%" is used. All other options will change the scale. As far as I know, the default option when printing is "Fit", which will often shrink the content by some percentage - because some often "invisible" or white background might be present in the file that extends right to the edge of the page format. Acrobat then thinks that the content goes beyond the "printable area" of the printer and will scale down the whole file. Hope that clarifies this potential pit-fall when printing PDF files. It might well be a different issue than the one I describe, but this is a very common source of error that I know. Andreas On 2021-05-27 10:02, John Antkowiak wrote: Hi, Jochen. Your suggestion sounds do-able; I'll play around with it and see if I can sort it out. I've got some digital calipers around here somewhere :) What I'm hearing is that the process of converting both the base map (and yes, I did create it in QGIS) and the parcel maps into PDF will distort the scale. (And that a print shop might compound the problem by manually fitting the source file to the printable area. Yes?) A question then is why didn't the PDF conversion distort them all the same way, to the same degree? The base maps are done now and I couldn't afford to do them again no matter what, so they are what they are. Going forward, is there an export option in Print Layout that will not distort the scale of the parcel maps? I am so relieved that someone has an explanation for this! - John A. - Forwarded Message - From: j.hu...@post-ist-da.de To: "qgis-user@lists.osgeo.org" Sent: Thursday, May 27, 2021, 03:33:12 AM EDT Subject: Re: [Qgis-user] Did scale change outputting to PDF? Hi John, as I understand it, you created the base map in QGIS. If you use the measure tool in QGIS to get the distance between two distinct features in the map (e.g. road intersections) and then measure the same distance on the printed base map with a ruler, it should be possible to calculate the scale. Maybe use two distances, one aligned more or less horizontally and one vertically, to check if the scaling is proportional. As Andreas pointed out, it is probably a problem with the settings when the PDF was printed. In my experience it is a good idea to go to print shops usually working for architects and engineers since they are familiar with the importance of scaling (for advertising etc. it is more important that the whole content is printed, so that scaling might be used to fit the output to the printable area without potential cropping). You can print directly to a plotter in QGIS if you have access to the device, avoiding the PDF detour. EPSG 2264 should be fine. Units should be US feet. Regards Jochen Am 27.05.21 um 07:15 schrieb John Antkowiak: Hi. This plan was too simple to fail - but it failed. The charity whose project this is needed a large (that is... massive) paper wall map on which to plot and rethink its delivery driver assignments. Both drivers and delivery addresses are subject to change from week to week but it's not a pizza delivery; this is a regular run to supply people in a bad way. So the plan was to print the base map (roads and road names and county boundaries only) and then print 8.5 x 11 address maps with parcel data and orthos. That way, the base maps don't change but the physical parcel layer is flexible. (On top of that is a third paper layer indicating which drivers go where so someone can stand back and take in the whole picture graphically. Not a cutting-edge state of the digital art solution, but not everyone is cut out for that. It is what it is.) In order for this to work, the parcel maps have to be the same scale as the base map. Which they were... in QGIS. We have to convert all the maps to PDF to pri
Re: [Qgis-user] Fw: Did scale change outputting to PDF?
Hi John, No - the PDF export does not distort the scale. But the printing of the PDF file might. It is absolutely important that - when printing the PDF - the setting "Actual size" or "Custom Scale at 100%" is used. All other options will change the scale. As far as I know, the default option when printing is "Fit", which will often shrink the content by some percentage - because some often "invisible" or white background might be present in the file that extends right to the edge of the page format. Acrobat then thinks that the content goes beyond the "printable area" of the printer and will scale down the whole file. Hope that clarifies this potential pit-fall when printing PDF files. It might well be a different issue than the one I describe, but this is a very common source of error that I know. Andreas On 2021-05-27 10:02, John Antkowiak wrote: Hi, Jochen. Your suggestion sounds do-able; I'll play around with it and see if I can sort it out. I've got some digital calipers around here somewhere :) What I'm hearing is that the process of converting both the base map (and yes, I did create it in QGIS) and the parcel maps into PDF will distort the scale. (And that a print shop might compound the problem by manually fitting the source file to the printable area. Yes?) A question then is why didn't the PDF conversion distort them all the same way, to the same degree? The base maps are done now and I couldn't afford to do them again no matter what, so they are what they are. Going forward, is there an export option in Print Layout that will not distort the scale of the parcel maps? I am so relieved that someone has an explanation for this! - John A. - Forwarded Message - From: j.hu...@post-ist-da.de To: "qgis-user@lists.osgeo.org" Sent: Thursday, May 27, 2021, 03:33:12 AM EDT Subject: Re: [Qgis-user] Did scale change outputting to PDF? Hi John, as I understand it, you created the base map in QGIS. If you use the measure tool in QGIS to get the distance between two distinct features in the map (e.g. road intersections) and then measure the same distance on the printed base map with a ruler, it should be possible to calculate the scale. Maybe use two distances, one aligned more or less horizontally and one vertically, to check if the scaling is proportional. As Andreas pointed out, it is probably a problem with the settings when the PDF was printed. In my experience it is a good idea to go to print shops usually working for architects and engineers since they are familiar with the importance of scaling (for advertising etc. it is more important that the whole content is printed, so that scaling might be used to fit the output to the printable area without potential cropping). You can print directly to a plotter in QGIS if you have access to the device, avoiding the PDF detour. EPSG 2264 should be fine. Units should be US feet. Regards Jochen Am 27.05.21 um 07:15 schrieb John Antkowiak: Hi. This plan was too simple to fail - but it failed. The charity whose project this is needed a large (that is... massive) paper wall map on which to plot and rethink its delivery driver assignments. Both drivers and delivery addresses are subject to change from week to week but it's not a pizza delivery; this is a regular run to supply people in a bad way. So the plan was to print the base map (roads and road names and county boundaries only) and then print 8.5 x 11 address maps with parcel data and orthos. That way, the base maps don't change but the physical parcel layer is flexible. (On top of that is a third paper layer indicating which drivers go where so someone can stand back and take in the whole picture graphically. Not a cutting-edge state of the digital art solution, but not everyone is cut out for that. It is what it is.) In order for this to work, the parcel maps have to be the same scale as the base map. Which they were... in QGIS. We have to convert all the maps to PDF to print them, and we had to send the base map PDFs to FedEx/Kinkos to print the 9 map grid panels at 42" by 62" each. When we got the big base maps up on the wall, we discovered the scale did not match the 8.5" x 11" parcel maps output to PDF and printed from home. It's not off by a lot, but it's enough to be painfully obvious from a single standard size sheet of paper. I don't know how to reverse engineer the big map scale precisely enough to enter a new scale number in the QGIS Print Layout. I didn't foresee it because this never would've been a conceivable scenario at the engineering firm where I picked up my meager GIS skills. (ArcMap sent a map directly to the plotter without interim steps.) There was no scale bar on the map. It shouldn't have been needed for this. Did something happen to the map scale when QGIS output the map to PDF? Could the size of the image on the pdf page have been adjusted manually or otherwise when being sent to a pl
