Origins of the Expression "On Tenterhooks"

By Jennie Shurtleff

Dating as far back as Biblical times, “fulling” was an important step in making woolen cloth. The fulling process (which used heat, moisture, pressure, and friction) increased the fabric's thickness while at the same time making the texture of the cloth smoother.  

In early times, the fulling process often involved placing the handwoven woolen cloth in a vat of stale urine, which had begun to age and form ammonium salts. Since ammonium salts are cleaning agents, these salts would cleanse the dirt and oils from the woolen cloth while also whitening it. As the cloth was soaking in this mixture, the person “fulling” the cloth (called “a fuller”) would pound or stomp on the cloth for hours to provide the pressure and friction needed to compress the fibers. While ammonium salts from urine were widely available, they were not the only cleansing agent used. Other early accounts describe a clay-like mineral substance called fuller’s earth being applied during the fulling process. While ammonia salts were able to break down the grease and dirt so it could be washed away, Fuller’s earth - which is highly absorbent - cleansed the wool by drawing the grease and dirt out.

After the cloth was cleansed and had reached the desired level of compaction from pounding and stomping, it was removed from the vat and hung on a frame that was edged with sharp hooks, called tenterhooks. These hooks held the cloth in place and helped to control the shape and amount of shrinkage as the cloth dried. The expression of being “on tenterhooks” means to be in a state of tension. It likens the tension that a person is feeling to what is happening to the cloth as it is stretched on a frame.

For those interested in the genesis of certain expressions, on Wednesday, April 6, 2022, at 2 PM, the Woodstock History Center will host a Zoom program that will explore the origins of other common idioms. Please visit the “Calendar” section of the Woodstock History Center’s website for more information and the link to this program.

Cloth, after being fulled, was placed on a frame with tenterhooks to control the shrinkage and to help insure the cloth dried in the desired shape.