(a) An establishment which is engaged in printing and engraving is not recognized as a retail establishment for purposes of section 13(a)(4). Therefore, employees of a stationery establishment engaged in printing and/or engraving do not come within the exemption. This fact will not affect the exemption under section 13(a)(2) of employees of stationery establishments who are not engaged in printing or engraving.

(b) In a combined stationery and printing or engraving establishment there are employees who operate the machines in the printing or engraving department and there may be other employees who also perform work primarily or exclusively for that department. There are in addition various employees in such combined establishments whose work relates to the stationery portion of the business but who also perform some work for the printing department. For example, office workers may keep records of both the printing plant and stationery department, maintenance workers may clean up in both departments; and warehousemen, messengers and stock clerks may handle material for both departments. In some establishments these workers spend relatively little time in the work of the printing department. As an enforcement policy an auxiliary employee will not be considered to be engaged in the making or processing of goods for purposes of the exemption under section 13(a)(2) in any workweek in which an insubstantial amount of his time (20 percent or less) is allocable to the clerical, messenger, or custodial work of the printing department.