Non-repro cross-section vellum of 100% rag content. Blue grid lines are accurate and exceptionally clear, sharp and visible, but will not reproduce on blueprints. All grids are printed on the underside of the paper to prevent removal during erasures. Pre-printed grids provide exact reference points for detailed drawings. Used by engineers, architects, graphic artists, etc., to make drawings and sketches to scale in either fractional or decimal dimensions. Available in a selection of grid sizes, packaged in rolls and 100-sheet packages.