PROCEEDINGS OF THE THIED ENTOMOLOGICAL MEETING 1047 



Hints on the making of originals. 



The following brief remarks are common to all processes : 



All originals should be as perfect as possible. When giving instruc- 

 tions for reduction linear measurements are understood ; thus, " half 

 size " means reduce to half the length and breadth, not half the area. 



Originals can be enlarged if necessary but this should be avoided 

 if possible. 



It is advisable to indicate by a short note if any particular point 

 in a scientific illustration requires special attention so that the engravers 

 can obtain the best result. 



Other methods of reproduction. 



Having considered the processes which are most commonly in use 

 at the present time we will briefly refer to other methods of reproduc- 

 tion which are available. 



Photozincography is the process which is the most useful for large 

 work such as the reproduction of maps and can be carried out in black 

 and white or in colours. 



A good drawing or sketch in black ink on white paper or tracing 

 paper can be enlarged or reduced by photography and a printing plate 

 prepared. This process is more economical in large size than the line 

 block process. 



Colours are introduced by difi^erent printings, each colour having to 

 be printed separately. 



Originals should show all the required lettering and detail and a 

 separate rough sketch showing the colours required should be supphed, 

 or a proof in black can be supplied by the printer which can be coloured 

 by hand as a guide. 



Wood Cuts or wood engraving are, as the name implies, blocks made 

 of wood. This is purely a hand process the quality of the work depend- 

 ing entirely on the engraver. It is not recommended as it is very diffi- 

 cult to obtain good work in India owing to the scarcity of good workmen. 

 Briefly, a drawing is made on a piece of box-wood and all the parts 

 which are not required to print are cut away from the wood by hand. 



Photogravure is a most artistic process but it is slow and expensive. 

 This is also a photographic process but differs from others in so much 

 that, instead of the printing surface being in rehef, the plate is prepared 

 so that the image is etched into the copper plate to varying depths 

 according to the origmal. Printing ink is forced into the etched portions 

 and naturally the places which are deeply etched take up more ink. 



