This Clear Etchant is great to work with. It ships in granule form. You can see through the tank and see how your metal is progressing. The etchant will turn a light transparent blue when the copper is etched from the metal. It can be heated to work faster as well. It also does not stain clothing and skin like Ferric Chloride does and doesn't require any electrical current to work. It is advisable to make sure it floats on the surface and agitation or a bubbler will help to give successful results.
This product is more environmentally friendly than ferric chloride.