A stem-back button is a button with a small stem emerging perpendicular to the back of the button. The stem has a hole that is used to attach the button to other objects. Stem-back buttons are commonly used for through-way cushions or pillows where both sides are tufted. A large upholstery needle is passed through the cushion. The end of the thread is tied to one button stem. The needle goes through the second button stem and back through the cushion from stem to stem several times with the thread pulled tight before being tied to a stem.
Prong-back buttons have a long set of two flat metal prongs emerging from the back of the button instead of a stem. During upholstering, fabric is used to cover the tufted surface while the back or underside of the furniture is still open. Holes are drilled in the wood frame, and prong-backed buttons are inserted through the fabric and into the frame holes. A washer is placed over the prongs. The button is pressed as tight as possible, and the ends of the prongs are bent over the washer to hold the button in position. Later, the back or underside is covered to hide the prongs and washers.
A button covering tool for stem-type buttons comes in two parts. The outer part is shaped like a cup, and the inner part is shaped like a mushroom. The head of the mushroom fits into the cup. The kit is sold with a pattern for the size of button. Cut your fabric in a circle matching this pattern. Place one fabric circle face down and centered over the cup-shaped bottom part of the tool. Press the fabric into the tool with the mushroom head. Insert the top half of the button face side down. Bend the fabric around the edges toward the center and push the mushroom tool over the ends. Insert the bottom of the button, stem-side up, and press the bottom into the top, using the mushroom tool.
If you are using prong-style covered buttons, go to your nearest upholstery shop to purchase the size and length of prong button you need. Bring your fabric with you. The upholstery shop has a large button tool that presses the fabric onto the buttons. For a small fee, the shop will place your fabric on the prong buttons. Always purchase a few extra in case you have problems during your upholstery project.