In a message dated 9/4/2007 8:13:21 P.M. Mountain Daylight Time, lhera...@bu.edu writes:
The red underneath the elbo is not exposed to ultraviolet. No UV no fade. Very few pigments in use in the early 1900s were color fast. Almost all of them fade and the color that they fade to, in most cases, is not what you would expect. And so...can we assume that the maroon accents fade but the amber horn color either does not fade or fades much less than maroon? I am simply wondering what pigment difference there might have been. The simplest answer would seem to be that certain colors absorb UV light more than others. I wonder what other present day horns would have been different colors when they were manufactured. ---Art Heller ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour From rich-m...@octoxol.com Wed Sep 5 05:35:48 2007 From: rich-m...@octoxol.com (Rich) Date: Wed Sep 5 05:38:45 2007 Subject: [Phono-L] Mystery In-Reply-To: <c47.1e91d39f.340f8...@aol.com> Message-ID: <20070905123605.6c990240...@mail.intellitechcomputing.com> Art, You can lookup the UV sensitivity of the various dyes and ground pigments used in the past. All you have to do is identify the original chemical composition of the finish you are interested in. This is NOT a trivial task. The linseed oil base also oxidizes to a yellow color, you might call it cream. There is some general information relating to water and alcohol soluble dyes and ground pigments in oil. You may have noticed that the interior of large art museums is dimly lit and the only direct light on the old master oil paintings is from a "print light". The print light is UV free. And that is only on when they are open to the public. The flag rooms are also dark and thew is NO flash photography allowed. On Wed, 5 Sep 2007 00:21:16 EDT, aph4...@aol.com wrote: > >In a message dated 9/4/2007 8:13:21 P.M. Mountain Daylight Time, >lhera...@bu.edu writes: >The red underneath the elbo is not exposed to ultraviolet. No UV no fade. >Very few pigments in use >in the early 1900s were color fast. Almost all of them fade and the color >that they fade to, in most >cases, is not what you would expect. >And so...can we assume that the maroon accents fade but the amber horn color >either does not fade or fades much less than maroon? I am simply wondering >what pigment difference there might have been. >The simplest answer would seem to be that certain colors absorb UV light >more than others. >I wonder what other present day horns would have been different colors when >they were manufactured. >---Art Heller >************************************** Get a sneak peek of the all-new AOL at >http://discover.aol.com/memed/aolcom30tour >_______________________________________________ >Phono-L mailing list >http://phono-l.oldcrank.org
