A printing system includes a converter for replacing graphic elements of a document (100) that is subject to subsequent processing such as color matching. Conversion involves using multiply transparency in place of overprint and creating transparency groups (21, 23) to replace elements (1-4) that have subsequent elements that meet an overlapping overprint criteria. An element transparency group (21, 23) includes multiple elements based on the original element (1, 3) but with geometry and selected colorant channels modified based on the relationship between the original element (1, 3) and each subsequent original element (1-4) meeting the criteria.