glassine

thumb|Printed glassine envelope for the photographer Arthur Weston, thumb|right|Glassine envelope

Glassine is a smooth and glossy paper that is air-, water-, and grease-resistant. It is typically available in densities between . It is naturally translucent, though dyes are sometimes added to the paper for color or opaqueness. Manufacturing takes place by first orienting the fibers in the same direction during the original pressing and drying followed immediately by supercalendering. Supercalendering passes the dried paper web through a stack of alternating steel-covered and fiber-covered rolls to increase density.