Hot Melt Gluing Machine adhesive (HMA), also known as hot glue, is a form of thermoplastic adhesive that is commonly sold as solid cylindrical sticks of various diameters designed to be applied using a Hot Melt Gluing Machine. The gun uses a continuous-duty heating element to melt the plastic glue, which the user pushes through the gun either with a mechanical trigger mechanism on Hot Melt Gluing Machine or with direct finger pressure. The glue squeezed out of the heated nozzle is initially hot enough to burn and even blister skin. Hot Melt Gluing Machine is tacky when hot, and solidifies in a few seconds to one minute. Hot melt adhesives can also be applied by dipping or spraying, and are popular with hobbyists and crafters both for affixing and as an inexpensive alternative to resin casting.