You don’t need to do much reading about weaving before you come across people talking about “fulling”. This is what happens when you agitate woollen cloth in hot water; each strand begins to mesh to the strands around it creating a thicker, warmer, fuzzier fabric.
You control the amount of fulling with different temperatures and techniques. Some people full by hand, others in a washing machine or dryer, but you need to keep an eye on the process, as different yarn will full differently. Some yarns apparently get to a point where the fulling takes off and in no time they go beyond what you hoped for!
Traditional fulling was often done by walking on the cloth (the surname Walker comes from this) and pounding or hammering were also often used. Kind of makes me feel sorry for the cloth.
So what if it’s not wool? Well, other natural fibres don’t technically full, but many will fluff up and are said to “bloom”. Here’s a before ‘n’ after of my soya yarn sampler from the last post:
Obviously, some fibres don’t change much at all (particularly synthetics) and “superwash” wool doesn’t behave the same way as other wools because it’s designed for machine washing.
Don’t confuse fulling/blooming with the results that a nice hot, soapy bath will have on any fabric freshly off the loom… all cloth will relax and soften as the water helps the fibres settle around each other and washes away any additional chemicals in the fibre.