"Tile "making," then, is done in powerful presses. Of the three main types of press available – the hand, the automatic, and the semi-automatic – the last named has proved the most generally useful; and of our total of no less than 140 presses considerably more than half are of this type. At the same time we have a number of completely automatic presses, operated, like those of semi-automatic type, by electricity, while for certain classes of work we still find hand presses the most serviceable. The making procedure is essentially the same in all three types. A steel well or "box" sunk in the bed of the press is filled with "dust," and a heavy steel die descends into it, forcing the dust against another die forming the bottom of the box. 

The pressure is such that the dust is knitted into a solid of the required size and shape – a plain tile, for example, a capping, a skirting – hard and strong enough to stand any reasonable handling. As the "green  tiles (so called in their unfired state) come from the presses, their edges, to which loose dust may be clinging, are lightly trimmed by hand; in technical language, they are "fettled." They are now ready firing, but an interval of at least a few hours, during which they may dry, will elapse before they reach that very important stage of their manufacture. "

From: "A Century of Progress 1837-1937" a publication to commemorate The Centenary of Richards Tiles Ltd.