Gilt edging, also known as gold edging or gold leaf edging, is a decorative technique that involves applying a thin layer of gold leaf or gold foil (another colors are available as well) to the edges of a book or other printed material. The process involves carefully applying the gold leaf or foil to the edges of the book using a special tool called a gilding knife. The gold leaf or foil is then burnished, or polished, to create a smooth and shiny finish.

     Gilt edging is often used to add a luxurious or premium touch to books and other printed materials. It is particularly popular for use on high-end or collectors' editions of books, as well as on special occasion invitations and other upscale printed materials.

     Gilt edging is a labor-intensive process that requires a high level of skill and attention to detail. It is typically done by hand, using specialized tools and techniques. The finished product has a distinctive, elegant appearance that sets it apart from other printed materials.