_Tar-acid resins for molding._—The present practice of molding resins is favorable to large-scale production. The shaping of the mold is expensive, involving skilled labor upon hardened steel; but once the mold is made it may be used to produce tens or hundreds of thousands of units. Subsequent labor upon the molded product is usually limited to the simple task of smoothing the line where the flash is broken off, since the product comes from the mold in the color and with the surface and shape desired. The usual arrangement at the present time is to have a battery of presses, grouped around central units which supply hydraulic pressure and steam for heat. A measured amount of molding powder or a pellet of compressed molding powder is applied to each cavity by the press operator, who controls by hand the time of application of heat and pressure and removes the article from the press. The cycle is a matter of minutes, and since each cycle produces a finished article if the molding is large, or a number of them if it is small, daily production per worker is high. The estimated average costs of the different elements in the process have been apportioned as follows: the cost of raw material is about one-third the cost of the finished product; and the combined cost of the mold allocated per unit, the labor cost per unit, and overhead the remaining two thirds.[5] On small runs labor cost and particularly allocated mold cost would be much higher, so that molding is usually uneconomic where only small quantities of the finished product are desired. In 1937 there were eight molders that produced their own tar-acid resins in whole or in part. One of these molders was the third largest producer of such resins. In the same year six producers of tar-acid resins for molding, including the first, second, fourth, and fifth largest, confined their activities to resin making. One producer of raw materials for tar-acid resins also made the resin on a moderate scale.