They are treated with a special combination of triple boiled linseed oils to resist ink bleeding. That same oil lubricates the punches in your stenciling machine each time a character is cut extending the life of your stencil machine. .015" thick oilboard is recommended for 1/2" and larger character height stencil cutting machines. Cut with grain of the board to maintain rigidity and it will not tear or pull when cut. Premium Marsh Canary Oilboards with finer fibers than the standard grade oilboard produce extremely clean cut characters.