Tack strip (US) (also known as gripper rod (UK), carpet gripper, Smoothedge (Can), tackless strip, and gripper edge) is a thin piece of wood, between 1 to 2 metres (3.3 to 6.6 ft) long and about 3 centimetres (1.2 in) wide, studded with hundreds of sharp nails or tacks used in the installation of carpet. They are nailed, tack side up, to the perimeter of the area being carpeted. After the underlay is installed, the carpet is cut to fit, stretched over the area and firmly anchored to the edges of floor via the tack strips. The strip has two functions: first, the tacks grip the carpet and permanently hold it in place and second, the carpet edge is jammed into the gap between the tack strip and the wall which gives it a finished look with little effort. This method allows a high quality, long lasting installation to be completed quickly and easily.
Tack strip was invented by Roy Roberts in 1939. This product revolutionized the power stretch method still used today for installing tufted carpet. "Gripper Edge" and "Smoothedge" were original trademarks made famous by Roy Roberts and his companies..