The primed canvas is most likely the problem. I would buy raw canvas if you can. Canvas is such a blanket term, but generally, the tighter the weave the better. This will help absorb the sizing solution well, not to mention holding detail....
A gelatin sizing, gum arabic, starch sizing, or arrowroot sizing would be a few options instead of acrylic. The pre-hardener that people use for silver-gelatin liquid emulsion should work really well. My girlfriend has used it for several different alt products on various subs with excellent results. It is expensive, however. You could try some thin coats of polyurethane to keep it simple/cheap and go from there if that isn't successful. Acrylic medium should actually work very well with canvas. Try this mix:equal parts white gesso, water and acrylic _gloss_ medium, and if that doesn't work, dilute the gloss medium more. You have to experiment. I have done acrylic on linen, canvas and paper for cyanotype with some success. Admittedly, there can be some mottling and less than smooth tonalities, but it really depends on the acrylic product. Canvas isn't the ideal substarte anyways, but can be really cool for some subjects. Don't buy cheap acrylic products! Here is a single-step Glyoxal/Gelatin a la Steven Livick: -Mix 6.5g of unflavored gelatin into 250ml of distilled water -Let bloom for about 30 minutes (blooming is the gelatin expanding) - After blooming, slowly raise temperature to 140f, but don't let it boil -After solution is warmed, add 10ml of a prepared solution of 40% Glyoxal and stir well -Allow to cool and apply with brush, puddle-stock etc. You might want to do a pre-shrink of the canvas in hot water prior to sizing/prepping the canvas for cyanotype. This solution should cover maybe an 11x14 paper so scale it up to fit your canvas and be generous. Gelatin serves to provide a surface for the cyano to lay on, the Glyoxal is a gelatin hardener that will provide some clarity/vibrancy to the tonalities of the actual photo. Don't discount the Glyoxal, it solves many problems and almost always improves dull looking prints. Good luck and keep at it! -Joe > yes, the primer is your problem. There's nothing for the chemical to soak > into. Anybody know of something he can put on it? > ----- Original Message ----- > From: "dennis vinciguerra" <vinciguer...@compuserve.com> > To: <pinhole-discussion@p at ???????> > Sent: Tuesday, November 26, 2002 8:05 PM > Subject: [pinhole-discussion] cyano on canvas > > > > Recently picked up a few cheap acrylic primed canvas panels for > > experimentation with cyanotypes. I brushed the chemicals on in the normal > > manner, allowed sufficient time to dry and then proper exposure . > > Immediately after placing the panels in cool water, the entire image > washed > > off. Is the acrylic primer my problem ? Any suggestions ? > > > > Thanks in advance, > > Dennis > > > > _______________________________________________ > > Post to the list as PLAIN TEXT only - no HTML > > Pinhole-Discussion mailing list > > Pinhole-Discussion@p at ??????? > > unsubscribe or change your account at > > http://www.???????/discussion/ > > > > > > _______________________________________________ > Post to the list as PLAIN TEXT only - no HTML > Pinhole-Discussion mailing list > Pinhole-Discussion@p at ??????? > unsubscribe or change your account at > http://www.???????/discussion/ >
