I 02 PATTERN-MAKING order to avoid the employment of loose pieces or of drawbacks. Core prints fall under two fundamental types, the " round " and the " drop " or " pocket " forms. Round Prints.—Tne^e are set either vertically or horizontally. The first-named have taper or draught, the second are, as a rule, parallel, invariably so when a pattern and its prints are jointed longitudinally through the centre to be withdrawn from cope and drag. They are tapered when they are attached to bosses or pieces that have to be left loose and be drawn hori- zontally back into the mould. Vertical Prints.—There is no recognized rule for the length or the taper of these. Both call for the exercise of judgment. As the diameters of prints are increased, their length or thickness a (fig. 14, A) is lessened re- . ' £••]» ii Fig. 14.—Vertical Core Prints, and Cores latively, because the larger diameters afford better support to the core at the bottom than at the sides. A print for example i ft. in diameter need not be more than J in. thick, while one of i in. diameter will be i in. long. Up to about 3 in., lengths and diameters are about equal, beyond that the pro- portionate thickness lessens. Prints are thinner at the top than at the bottom (fig. 14, A). Usually they need not be more than half the thickness, since they have not to support the core, but only to steady it against risk of lateral displacement during pouring (fig. 14, B). Bottom prints may have from J in. to J in. taper on the diameter. Top prints should have more, because the sand in the cope has to be lowered on the upstanding core, with risk of a crush if the taper is not ample. Often, to avoid this risk, the portion of the core that enters the print impression has an excess of taper, with the result that close contact does not occur until the cope is down to its bedding. (Compare c and D, fig. 14.) It is desirable in work that is standardized to put the taper in the core boxes. Ordinarily the moulder rubs the taper on the cores to match the print impressions, and his is a frequent cause of inaccurate setting.