DUPLICATING PROCESSES : As we mentioned earlier duplicating is a process whereby a master copy is prepared from which a large number of other copies are obtained with the help of a duplicating machine. It is a substitute for printing. It is used when the number of copies required is more than the capacity of a typewriter and yet not large enough to justify printing.
There are three main duplicating processes. These are listed in increasing order of cost and copy quality.
1. Spirit duplicating
2. Stencil duplicating
3. Offset litho duplicating
These three processes require duplicator and special material for making copies. Thus there are spirit duplicators, stencil duplicators and offset litho duplicators. Besides you may come across others such as electronic stencil duplicators and type set duplicators.
The duplicating machines available in the market can produce 200 to 500 legible copies of letters, circulars, notices, reports, forms, price lists, etc.
Let us now consider equipment, materials, master preparation and making of copies in each of the processes listed above.