Lawrence Ferric Chloride granules are used to mix up a solution of ferric chloride for etching purposes. Proportions recommended vary depending on the speed and accuracy of the etch and the metal you are using, therefore testing for your own application is always necessary.
The strongest ratio will be 1 part ferric granules to 1 part water which will give the fastest but least accurate etch, and anything stronger will have the effect of slowing down the etching process. A weaker solution, for example, 2 parts water to 1 part ferric granules will make a slower but cleaner etch that is more controllable and more appropriate for aquatints.
Caution: When diluting, add the granules to water very slowly, as the combination generates heat and avoid metal containers and utensils. Ensure appropriate protective clothing is worn to avoid contact with skin and eyes. Avoid inhaling fumes.
