In Transfer Printing the question of rapid drying is very important, and in Direct Tin Printing it is even more so. Arrangements of a somewhat extensive character must be made for the reception of metal plates immediately after printing, so that the air may freely circulate about them, and thus assist in the drying. The room in which the printing sheets are thus stored must be free from dust, for it will readily adhere to the tacky printing ink, and afterwards prove a source of endless trouble.
Fig. 26.
Drying racks of various descriptions are used for the storage of printed metal plates. One of the best is constructed on the lines shown in [Fig. 26]. The shelves A A are adjustable so as to carry plates of different sizes. The printed sheets are set up on end in the grooves B B, and by arranging them back to back in pairs a large number can be accommodated without hindering the drying. Other types of drying racks are shown in the sectional drawings (Figs. [27A] and [27B]).
Fig. 27a.
The question of air-drying versus stoving has ever been a contentious one, and admits of considerable diversity of opinion. Air-drying is preferable where convenient. It is much more economical than stoving, of course; but, on the other hand, it might be a better plan to stove a printing than to wait, perhaps for some hours, until it dried naturally. With some printing inks and under certain climatic conditions both may be necessary, so it is almost impossible to lay down any hard-and-fast rules as to the adoption of either plan.