Clean printing can not be done from dirty type. For this reason, as well as for greater ease and cleanliness in handling, it is important that type (which has to be used over and over again) should be washed as clean as possible after use. Ink should not be allowed to dry hard on a form, as it will if left over night or over an idle day. The type face should be cleaned after taking proofs. It should show a clean face while corrections are being made, and also when it goes to press or to the moulding room.

Type should not be distributed back into the case until it is well cleaned after use.

Benzine is now very generally used to wash ink from type, electrotypes, and other printing plates. When it can be obtained in good quality it is a convenient washing fluid for printers’ use. It loosens up dry ink quickly, evaporates in a few moments, and leaves the surface dry.

Benzine and other type washes are often used with a brush, but this is not a good practice. The brush cleans the ink off the face of the type, but does not carry off the ink, which is left to dry again down in the hollow parts of the form and around the shoulder of the types where the fluid has washed it. A brush soon becomes foul after repeated use; it cannot be easily cleaned; it is usually retained in this condition and while it rubs off the face it leaves greater foulness than it can take away.

A soft rag rolled into a pad with a little benzine poured on its surface will loosen the ink and take it off the type clean. When the pad gets inky turn another part of the rag out to give a clean wiping surface. When the rag gets dirty enough to soil the hands throw it in the waste can and get a clean one.

Quite often, after the ink has been wiped off with a rag, a fairly stiff, fine brush is needed to clean out dried ink and dirt that has accumulated in small places like the counters of the letters and the screens of halftone plates.

Gasoline is a tolerable substitute for benzine when the latter cannot be obtained. It is not so satisfactory, however, because of the greasiness which it leaves on the surface after evaporation. If the form is to be re-inked immediately after cleaning this greasiness must be removed in order to ink up again for a sharp, clear impression.

Kerosene may be used for washing off ink, but it also leaves a disagreeable greasy surface, even more than gasoline does. For this reason it is not satisfactory for frequent washing of type or printing forms, though it is a good wash for inking rollers.

A weak lye, made from dissolved potash, was formerly used extensively for washing type forms and inking rollers, but its use has been superseded by the safer, cleaner, more convenient benzine or gasoline. It is excellent, however, for washing type forms occasionally, as after a long run on the press or after electrotype moulding, to clean off the accumulation of dried ink or of moulder’s wax and blacklead.

For cleaning with lye the form should be stripped of all wooden material like reglets, wood-base plates, and anything that is liable to be injured by the washing. The type should be placed on a board and set in the sink. The washing is done with a medium stiff brush, care being taken not to allow the hands to get wet with the lye, as the solution will burn and discolor the skin. After a thorough but not hard rubbing, the lye is rinsed off with running water until it has all disappeared. If the type is still a little greasy to the touch after rinsing there is still some lye to be cleared off by further rinsing.

Caustic soda may be dissolved and diluted to the right strength and used in the same manner as potash lye.