HO THE A B C OF PHOTO - MICROGRAPHY 



light, and the paper, after sensitizing, must 

 not be exposed to the latter except in print- 

 ing. It is much less sensitive than a silver 

 coating, but the whites will lose in purity by 

 a very short exposure to daylight. Printing 

 should be done by direct sunlight and con- 

 tinued until the details are well shown in a 

 dirty bronze color. The prints should then 

 be placed, face down, in a tray of water for 

 a few moments, then washed through several 

 changes and finally dried between sheets of 

 smooth blotting-board under gentle pressure. 

 A picture thus made is absolutely permanent, 

 and, with its brilliant blue tint on a snow- 

 white ground, " a thing of beauty and a joy 

 forever." 



Finally, as to printing methods on paper, 

 I would advise the use of a deep printing 

 frame with glass front and of ample size, say 

 6%x8% (my own favorite) not too large, 

 easy to handle, " just right." A spoiled nega- 

 tive from which the film has been removed 

 will answer for the front, but a sheet of thin 

 plate glass is much better, as it is perfectly 

 flat. The breaking of a negative from un- 

 equal pressure in such a frame is well-nigh 

 impossible; all sizes, from quarter to full 

 plate, may be printed in it, and in making 



