Think of a colouring book, but made of fabric and big enough to cover your lap on the sofa. Most measure around 150 x 125 cm and come with a set of pens in the box.
The design is large, so it works best a little at a time rather than in one sitting. It is one of the few hobbies a whole household can share on the same piece.
White lines on black make every colour stand out, even the lighter ones. Choosing the design is half the fun, so it is worth looking at the whole pattern first.
The question people ask most is about washing. According to the manufacturer, washable water-based ink comes out in a normal wash, leaving the printed outlines ready for another round. Check the care label before the first wash.
Some people switch to permanent pens for a finished blanket they want to keep as it is. You can mix both on the same project, as long as you remember which parts will stay.
A few practical tips help. Colour on a flat surface so the fabric does not stretch, and close the pens after each session so they do not dry out. A quick test on an edge shows how strong each colour looks.
It is an easy way to keep your hands busy while chatting or listening to music. It is also a popular Christmas gift idea, as it is still useful once the colouring is done.