This is a thick type of wool, sourced from a particular type of sheep, named, as you might guess, Merino. Originating in 12th century Spain, it found its way to Australia and New Zealand, resulting in modern Merino. Unlike other types of wool, it is hypoallergenic. It retains its shape well and is suitable for all types of projects.
Some types of Merino may be machine washable, but always check to be certain. If not, wash in slightly warm water.