may be from about 1 100 to about 100 1 by weight but a preferred ratio is from about 1 10 to about 5 1 a particularly preferred ratio is from about 1 4 to about 1 1 the neutralization power of the combination is preferably sufficient to reduce the ph of the resin solution to that of a substantially neutral solution i e one having a ph in the range of from about 6 0 to about 7 0 when the ratio of magnesium salt to aluminum salt is very high it may be necessary to add a small amount of acid to achieve the desired reduction the use of an acid salt such as sodium bisulfate in an amount equal to or less than the combined weight of the aluminum and magnesium salts is contemplated to augment the neturalizing power of those salts and reduce the amount of insoluble hydroxides in the following examples which illustrate the invention in more detail a 100 ml sample of a 3 sodium hydroxide solution of a photoresist resin containing 40 mil sq ft of dynachem 39 s laminar u00ae hg dry film per gallon is neutralized by the addition in the given ratios of a mixture of mgso 4 7h 2 o and except where noted a technical grade of.