Small Batch for Freshness
Many suppliers supply Collodion U.S.P. with a concentration of nitrocellulose that varies from 4 to 10%. This means your collodion formula may contain double the amount of nitrocellulose needed to work properly. This changes the drying, surface characteristics, and the aging of your collodion. This is one more variable in a process that has so many.
Our Collodion is made in small batches and has 4% nitrocellulose by weight (5.1% by volume). Most of the contemporary formulas were formulated using 4% collodion. This means your collodion formula will work as intended.
Most of the historical formulas contained 1.0% to 2.0% Nitrocellulose by weight. If you use a collodion with 7% nitrocellulose in your formula you could have twice the amount needed.
Too much nitrocellulose gives you a thicker collodion that may result in crepe lines, thick edges and longer fix times.