SPECTRAFIX PASTEL FIXATIVE
SpectraFix is a casein-based pastel fixative that utilizes milk protein and grain alcohol to provide you with a non-toxic, fully archival fixative for pastels and other works on paper. The 2oz bottle of concentrate will make 16oz of fixative.
Which type of alcohol should I mix with SpectraFix Concentrate?
You can use any clear, unsweetened, plain alcohol to dilute SpectraFix Concentrate, however, you will need to make sure that it is 40% – 60% diluted, otherwise the alcohol will be too strong and may cause the casein to curdle. Straight vodka works well for this, as it is 40% right out of the bottle. Rubbing Alcohol works too, but if you use the 93% Rubbing Alcohol (Isopropyl) mix it 50/50 with water, which should make it a 45% alcohol solution.
There have been rare reports of some cheap vodkas or rubbing alcohols causing the casein to curdle into lumps, and this is a result of very bad alcohol distillation and harsh chemistry. Almost all brands won’t do this, and I’m afraid we can’t name the ones that do, since it is a bit of a random rarity, but make sure you TEST FIRST!! Just mix a little alcohol with the concentrate, and if it remains as a milky solution with no visible stringy lumps forming, you should be good to go!