987. Intensifying

Intensifying. The negative is then intensified by the use of the solution, which has to be determined by the quality of the negative, and after this operation the negative must be "blackened."

988. If, perchance, the negative is found to be too strong both in the high-lights and the shadows, it may be improved by the use of the reducing formula.

989. Local Treatment

Local Treatment. The manipulation of the negative in all of these particulars, and also treatment locally - working up small parts to bring necessary gradations of tone - depends entirely upon the skill of the operator.

990. If the negative has been made with the use of a prism, it is necessary that it be dried in an oven and then coated with a gum arabic solution, made by mixing 2 ounces of gum arabic and 12 ounces of water, or any of the negative varnishes that are on the market. (Note: While practically all engravers use the prism and thereby save the reversing of the films, yet where the prism is not employed and a straight negative has been made, it is necessary to strip it to get it reversed.)

991. After the negative is dry and cool, coat with

Rubber Solution.

Rubber Cement ...........

....................3 ozs.

Benzine

...................20 ozs.

992. Then let dry and coat with

Plain Collodion.

Ether ....................

8 ozs.

Negative Cotton

...................120 grs.

Alcohol ..................

8 ozs.

Castor Oil ...............

.....................1/4 oz.

993. Then dry with heat. The castor oil is added to make the film adhere to the glass after being turned. When cool, cut negative to size and shape wanted, then immerse in

Solution of Acetic Acid.

1 part Acetic Acid. 8 parts Water.

After laying in acid for about five minutes, negative is ready to strip.

994. In mixing up all formulae, of course smaller quantities of solution can readily be made by following out the same proportions as stated.