Because you told me technical grade is not good enough for photo work. Further, you said it was not possible for technical grade to have 0 insoluble particles, even though 20 Mule Team Borax from the grocery store is claimed not to be abrasive. Third, because you could not, or ar least did not point to a place where one could find the specs required of Photo Grade borax. At the time I wrote this, I did not know that the specs for technical granular and powder were not the same. Fourth, it takes little time to prepare a gallon or more of borax solution of known weight percentage and of a higher grade than technical, whether it started as granular or powder. Fifth, because there might be some among us who do not know that a solution saturated at a given temperature has a known concentration and can be measured out on a balance more accurately than by weighing the powder directly, even though the temperature is higher that that at which the solution was made.
Originally Posted by Kirk Keyes