Fuming an Aged Old Process Given New Life

From the Past to the Present: The Art and Craft of Fuming Hardwoods

Much of the beauty of Gustav Stickley’s Arts and Crafts furniture is derived from the careful wood selection and his insistence on finishes that did not obscure the natural look and feel of the wood. The unique design of his Morris chair is trademarked by beautiful character marks of quarter sawn White Oak that was not to be obscured but enhanced by his fumed finish process.

He devised this finishing process to achieve the low-key, almost sensual look and feel he wanted.

Fuming – An age old method that has been resurrected to once again reveal the beautiful grain of wood. This process gives wood a distinctive brown appearance and highlights the rays of quarter sawn oak.


Fuming wood flooring chemically changes the color of the wood. The procedure involves putting the oak in a closed chamber in which commercial grade ammonia is introduced. This chemical is a commercial grade of ammonia that is stronger than the household grade and produces a stronger effect. The darkening effect of the ammonia is a chemical reaction with the tannins that are naturally in the wood’s chemical make-up. It is not the application of the ammonia to the wood, but rather the fumes reacting to the tannins in the wood that produce the color change. Sometimes an additional application of tannic acid is applied prior to the ammonia exposure to the wood to deepen and darken the color.


Fuming Oak


The longer the wood is exposed the darker the color reaction. This is why this procedure is sometimes referred to as reactive staining or reactive finishing. This chemical staining process does not involve pigments or particles that mask the grain or figure of the wood. The results can range from a rich brown to almost black. The length of exposure can vary from 3 to 5 days depending on the desired color.

Like many things it is reputed that the process was found by accident. Dating back to the turn of the twentieth century it is thought that the discovery was made in horse stables. The beams above the horses were noticeably darker compared to the beams in other parts of the stable. The darkening process was attributed to the ammonia in the horse’s urine. This can be more commonly seen as pet stains on hardwood floors that is also a reaction of the ammonia to the wood.

This process became Stickley’s finishing signature in the Arts and Crafts movement and is extremely popular today.