Making copies by photocopying methods
Translucent paper and dyeline copying
It may sometimes be economical to print the stock of blank forms on paper which is translucent to ultra violet light so that it becomes possible to obtain a number of copies of the form (as completed after use) by the dyeline process.
This method has advantages when:
- It is not practicable to obtain the desired number of completed copies when the original entries are made, e.g. when a document is completed by a member of the public and it is unreasonable to expect more than one copy or because it is not practicable to obtain all the copies required by more conventional means such as carbon
- the number of copies required varies according to circumstances
- it is necessary to take copies of the entries on documents periodically, and when the quantity or nature of the entries on those documents varies on each occasion. For example, a ledger sheet printed on translucent paper becomes the ‘master’; the account can then be compiled, day by day, by handwritten or typed entries and whenever necessary, e.g. at the end of an accounting period, the ledger sheet can be totalled and the appropriate number of copies produced by the dyeline process to serve as an invoice or statement of account.
If translucent masters are to be prepared in manuscript, the use of a carbon black ink is important, since ordinary writing inks seldom give a sufficiently dense image. The use of pencil or ball pen should be avoided; if pencil must be used a soft degree should be selected. There are several kinds of translucent paper available, ranging from a high grade bond paper which has the appearance of an ordinary typewriting paper, to certain types of tracing paper which are much faster printing, but are not particularly attractive in appearance. The advice of H.M. Stationery Office should be sought as to the most suitable grade for the work in mind.
Diazo (dyeline) paper is coated with an emulsion which is sensitive to ultra-violet light; when exposed this emulsion becomes inactive, but the parts which have been protected by the dark lines on the translucent master will, by the application of certain chemicals or ammonia gas, form a dye image. For this reason the copy is often called a ‘dyeline print’. The paper can be handled in any room lighting so that no dark room etc. is needed and the equipment is designed for use on an office desk.
Photocopying and other reproduction methods may sometimes be employed to obtain copies of forms and entries thereon.