Leather glue spreaders are commonly a flat-edged tool made of plastic. They allow for even spreading of glues over flat surfaces, allowing the layers to be very thin, or glue focus on a particular spot. after used, they can be washed and reused, as maintaining the clean edge is very important to a smooth spreading of the glue.
Glue brushes are also an options when spreading glue. They are dipped into a liquid adhesive and then applied to the leather. They allow larger volumes of glue to be applied more quickly, though aren’t as precise as the glue spreaders. The spreaders are an easy way to target glue placement and preferred volume.