"Letterpress Printing Line" means a web or sheetfed printing line that does not constitute a flexographic printing line, in which the image area is raised relative to the non-image area and the ink is transferred to the substrate directly from the image surface.
Ill. Admin. Code tit. 35, § 211.3305
Added at 34 Ill. Reg. 9069, effective June 25, 2010