If you can find it,
Crocein Scarlet aka New Coccine (Kodaks name)
Mix 1 part dry to 16 parts water (stock solution) dilute it down for working this is the stuff us old timers used and still use. A small amount goes a long way. Oh and be careful is will stain every thing it get on. Kodak sold it in 1 or 2oz bottles which should last 10 life times.
You might look at e-bay for some it is some times used in ceramics