When someone talks about 'relief printing' they are usually referring to letterpress, woodcuts, wood engravings, or linoleum cuts. Relief printing encompasses a broad range of techniques and possibilities for artists and designers. This is especially true for the book artist because of its history in the production of books. Relief printing allows for extremely clean, sharp lines and beautiful tactile readable texts while woodcuts have many expressive mark-making possibilities.
Relief printing involves a print matrix which has a raised surface.
The raised surface is what prints. In woodcuts, linoleum cuts, and wood engravings the recessed areas are physically removed with carving tools. Others, like lead type, which is cast from matrices specially designed for the purpose, are machine made. Today, casting type from lead is done on a limited scale but was once the industry standard for printing most text. It has also become common to photographically produce relief plates with text or images on magnesium and photo polymer plates.