Effective home photoetching supply

I am looking for the most effective home photoetching supply. I have
made a true etched plate in the past on bronze and nickel, but not
with precious metals. I do not remember which product I used for the
resist where it was purchased. What is the best product to use on
silver and gold? I am looking to etch fine-detailed patterns, and am
not satisfied with iron-on resists.

Any suggestions?