The item "printing" when used in an appropriation Act means and includes expenditures for contracted services, materials and supplies where the principal function or purpose of the resulting product is the dissemination of printed information. These costs include all types of printing processes such as letterpress, offset and gravure, but not expenditures included in "commodities" as defined in Section 15b and "electronic data processing" as defined in Section 24.1.
30 ILCS 105/15c