A Gilder's Knife, sometimes called a "Gilding Knife" is tool designed to cut loose sheets of metal leaf on a gilding cushion during the gilding process. The edge of the knife is just sharp enough to cut the metal leaf, but not so sharp that it cuts through cushions. Gilding knifes are normally chisel-like in shape, with two sharp edges, one either side and a square tip.

How to use a Gilders Knife:
When applying metal leaf, the square tip is useful for manipulating the leaf. Once the sheet is cut (if desired) in a gentle sliding motion lift one edge of the leaf with the gilders knife and lay it across the surface being gilt, manouver further with the tip of the gilding knife before completeling the process with a gilders brush.  

How to choose a good Gilders Knife:
A good quality gilding knife will come with a sleeve in which the knife is stored, its very important that the gilders knife stays in perfect condition as any little burrs would otherwise catch the gold leaf during application. So when buying a gilders knife it is worthwhile buying an expensive one that will serve you well for many years to come. If you are unsure of exactly what gildign tools suit your skill level perhaps considering joining a gilding workshop, where you can trial various tools, learns about them and seek advice from the gilding teacher.

Where to buy a Gilders Knife:
The best place to buy gilding tools, equipment and supplies is from a specialist gilding supplies store, alternatively a good quality art supply store will often also stock gilding knives.