and crystallizes his concept of what the report should be, the more efficient and 

 productive will be his efforts in writing the report. 



An outline is used in a report as a table of contents, which serves, together 

 with headings and transitional elements in the text, to keep the reader oriented as 



PROCESSING THE PLATE 



The dichromated albumen process is the standard method of 

 preparing zinc lithographic plates. All other plate-making pro- 

 cesses for zinc are modifications of this one, which is herein 

 discussed under the headings 



Treatment of the Image 



Treatment of the Non- Image 



Treatment of the Image 



The treatment of the image involves three steps: cleaning, 

 sensitizing, and arcing (Sayre, 1939, p. 50). 



Cleaning : Because zinc is readily oxidized upon contact 

 with air, a zinc plate must first be covered with a layer of zinc 

 oxide. Dilute hydrochloric acid, which reacts with the oxide but 

 not with the pure zinc, is used to remove the oxide. Soluble zinc 

 chloride, the product of the reaction, may be washed off the plate 

 with water. 



Sensitizing and Arcing : The sensitizer, a light-sensitive 

 solution of ammonium dichromate and albumen, is spread in a smooth, 

 uniformly thin layer over the plate and allowed to dry. The plate 



Figure 39-1. Sample report page illustrating a format for three levels of headings. 



783 



