Reprography
In order to disseminate information widely some method of reprography is invariably used. Reprography is the science and practice of copying documents by photography or xerography. You may have used a xerox machine for making copies of your degree, grade card, application forms etc.
The scope of reprography is wide, covering areas such as duplicating, document reproduction and copying, including photographic copying.
The wide range of methods can be divided into two basic techniques.
(1) Duplicating, and
(2) Copying.
Though the terms appear to imply the same process, technically they are different. One of the fundamental differences is that in duplicating a special, master has to be prepared from which copies are made. The duplicating process will often eventually expend the master. With copying however, copies are made directly from the original which remains intact for further use. The choice of method will depend on the facilities that are available in an office, the number and quality of the copies required, and cost.
Here we will consider some of the more usual processes from the point of view of convenience, copy quality and cost. The knowledge of those processes is essential because you will certainly require using them sometime in the lab office.
Before we discuss duplicating processes and requirement of material and machine, we must consider various kinds of typewriters commonly available in labs and their uses. Besides routine work typewriters are also used for cutting stencils about which you will learn.