Think of a coloring book, but made of fabric and big enough to cover your lap on the couch. Most models measure around 59 x 50 inches and come with a set of markers in the box.
The design is large, so it works well a little at a time rather than in one sitting. It is one of the few hobbies a whole household can share around the same piece.
Many designs are printed as white outlines on a black background, which gives a stained-glass look once colored. A busy pattern keeps you going for weeks, while a simple one can be finished in a few evenings.
What makes these blankets different is the washable ink. According to manufacturers, washable water-based ink comes out in a normal machine wash, leaving the printed outlines ready for a new round. Always follow the care label on your blanket.
Some people switch to permanent fabric markers for a finished blanket they want to keep as it is. Just keep track of which areas were done with which ink.
A few practical tips help. Work on a table with the fabric pulled flat, and cap each marker as soon as you are done with it. A quick test on an edge shows how strong each color looks on the fabric.
Many adults treat it as a relaxing hobby, something to do with their hands while talking or listening to music. As a gift, it works for people who like crafts but already have plenty of coloring books.