Photographers' Formulary will be selling dropper bottles of erthyrosin(e) solution soon. It will be in a dilution standardized for emulsion sensitizing. Either Bud or I will let you know when it's ready to order. In about a month, The Light Farm will be posting two ortho recipes using the Formulary's solution. Other sources of erythrosin can be used, of course. It's not expensive (as these things go) but a very little goes a very long way and it can be a mess to mix up, so the Formulary is offering a great service to us.
A note about McCormick food dyes. The regular red color is not erythrosin (FD&C #3). It is made with #40, which is not a sensitizing dye. It is the McCormick "Neon" set that has Neon Pink, which is made with #3 and #40, that does the trick. http://thelightfarm.com/cgi-bin/html...tent=18Jan2012