8 



a minimum quantity of rosin to insure good erasures; it should be 

 neutral, or nearly so; should not be loaded; should be loft or pole 

 dried rather than machine dried, and should have a smooth, even 

 surface. 



BOOK PAPERS. 



For publications of permanent value book papers should be of the 

 same general character as record papers. The sizing should be of 

 rosin alone. When loading is used it should not exceed 10 per cent. * 

 For less valuable books papers of lower grade containing, in addition 

 to rag stock, chemical wood pulp, esparto, etc., maybe used and less 

 care exercised in their making. For books and papers of transitory 

 value rag stock need not be used, second-class stock, such as chem- 

 ical wood pulp, esparto, etc., serving every purpose. Overloaded 

 papers should not be used for any class of work, as they are needlessly 

 heavy and much weaker than the same paper unloaded. Loading 

 makes a paper more opaque and better suited to the use of certain 

 inks ; it also serves as a substitute for beating, in that it hides imper- 

 fections in a poorly made sheet. For books containing a large number 

 of pages a thin paper, provided it is sufficiently opaque, should be 

 used, in order to secure a volume of good proportions. For coated 

 papers the same general specifications hold, except that more loading 

 is permissible. 



WRITING PAPERS. 



The best grades of writing papers used in correspondence which 

 partakes of the nature of permanent records should be strong, uni- 

 form, well-made rag papers not loaded and quite similar to record 

 papers. A cheaper paper may be used for less permanent corre- 

 spondence, being of poorer quality as to stock, texture, etc. 



ENVELOPE PAPERS. 



As envelopes are but short lived they need not be of the strong 

 rag papers described above. It is sufficient that the envelope have 

 a good writing surface, be opaque, and strong enough to carry its 

 contents safely to their destination and appear well when delivered. 

 Any stock and character of paper of the desired color which will 

 fulfill these requirements will serve the purpose. For instance, a 

 well-made paper containing 50 per cent of rag and 50 per cent of sul- 

 phite stock is satisfactory for the ordinary correspondence envelope. 

 Very strong papers are of course necessary for international use or 

 the transmission of large and heavy documents. Envelope papers 

 should not be loaded, should be well sized, and have an even, firm 

 surface. 



[Cir.34] 



