During development, Ammonium Thiocyanate together with HC Developer acts as a complexing agent, extracting silver and depositing it on the plate’s surface, resulting in a white negative that against black background renders as positive. The amount of AT must to be precisely adjusted according to the specific emulsions being used. For Zebra Dry Plate Tintypes, only 3g per 300ml is required.
The size of the silver particles deposited on the surface by Ammonium Thiocyanate determines the hue in tintype positives. The temperature of the light and the developing time also play a significant role. The ideal development results in a warm milky white hue, with longer development times leading to bluer whites. The quantity of Ammonium Thiocyanate used is another important factor, with more AT resulting in smaller silver particles and cooler reflected light, while less AT produces larger particles and a warmer hue. For example, using 7g instead of 3g of Ammonium Thiocyanate in the recommended formula can yield a prussian blue hue.
* 30g of Complexing Agent is sufficient for developing about 40-50 4×5 Zebra Dry Plates (in case you need larger quantity contact us on zebradryplates@gmail.com)
** Fore details and recipes check out the Zebra Dry Plate Tintype User Manual available HERE.
****For Chemical Safety Summary Datasheet click HERE.
