S.C. Code Regs. § § 117-309.5
Where persons contract to manufacture, compound, process, or fabricate their materials into articles of tangible personal property according to the special order of their customers, the total receipts from the sales of such articles are subject to the sales or use tax, whichever may apply. The seller may not deduct any of his costs, nor can he deduct any of his charges for labor or services, which are an item of the production or fabrication cost of the articles, to arrive at the taxable amount. Articles commonly made to order are portieres, curtains, draperies, tents, awnings, clothing, convertible tops, seat covers, and slip covers.
Persons making sales of made-to-order and custom-made articles purchase the materials which become a component or ingredient of their products at wholesale, tax-free. The equipment, tools, and supplies used or consumed in the production of such articles, and not becoming a part thereof, are subject to the tax.
S.C. Code Regs. § 117-309.5