=Sizing may be Avoided= if each picture, after well drying, be dipped into the following solution: Water 500 g., borax 130 g., white shellac 100 g., carbonate of soda 6g. The borax and carbonate of soda are dissolved in boiling water, and the powdered shellac then added in small quantities; when solution is complete carefully filter and allow to cool. The impressions, two and two, back to back, are pinned on frames, dipped in the varnish, and afterwards dried. By this procedure a shellac coating is given to the surface only of the print; there is no gelatine substratum to soften through atmospheric influences, and so crack and destroy the layer of varnish. In winter the temperature must be kept high, and the solution should be heated 15° to 20° C. =Parchmentising= to a slight degree may also be adopted to close the pores of the paper. Add one part by volume of water to two parts of sulphuric acid, allow it to become quite cold, immerse the pictures for one second only, and at once wash in a copious supply of clean water to which has been added a small quantity of ammonia to effectually neutralise the acid. The action of the acid must not be carried too far, as it is merely necessary to act on the surface. To prevent paper so treated from cockling while drying, it must be put under pressure or stretched upon a frame; when quite dry it has to be varnished and dried by heat. =Varnishing Enamel Paper= without previous sizing is best done by means of an alkaline solution of shellac prepared as follows: Place in a six litre tin flask 1/2 kilo of bleached and powdered shellac, pour over it 1-1/2 kilo of alcohol and 1-1/4 kilo of strongest ammonia. In the course of a few days the solution of the shellac will be complete, then add, with constant stirring, 2-1/2 kilo of hot water, and when cold filter. It may be applied to the print with a broad Blanchard brush,[K] and left to dry in a horizontal position. The prints may also be floated on the varnish for about half a minute, and then suspended to dry by means of clips. After a few minutes have elapsed a piece of blotting paper should be applied to the bottom edge to absorb the superfluous varnish. [K] Made as follows: Take a piece of glass, say 20 cm. long by 6 or 7 cm. wide, and a piece of swansdown calico the same width as the glass but only 6 cm. long, fold this over the one end of the glass, 3 cm. being on each side, and bind round with thread or spring on a rubber band. =Rolling or Burnishing= must on no account be attempted until the mounted prints are perfectly dry, otherwise they may be seriously damaged or even completely torn from the mounts. CHAPTER X. OTHER COLLOTYPE PROCESSES.