To wash or not to wash, that is the question
Are you happy with the hand, color, and density of your unwashed wool? Leave it alone.
If it is not dense enough, fluffy enough or the colors are too sharp, by all means wash and dry the fabric.
Please, however, experiment with a small piece to determine how the wool will react to the heat and agitation of the washer and or dryer. Surprise excess shrinkage is not correctable.
Washing and drying should tighten the fabric (less fraying), fluff the fabric (raise the fibers on the surface), and soften the colors in the fabric. The softening of the colors is caused by the raising of the fibers on the surface which interferes with your eyes’ ability to see the shades clearly. The more different color fibers in the fabric, the more possible change. Some fabrics after being washed are so different they even look hand dyed.
Nobody knows what is going to happen when they wash their different woolens. Factors that determine shrinkage when washing are heat agitation, and length of wool fibers in the cloth. In general a softer woolen fabric will shrink more and woolen system yarns will fluff more because the yarn contains some shorter fibers. All you can control are the heat and the agitation.
Remember: Experiment so you don’t get an unpleasant surprise, and you can always wash again with more heat and agitation. Hope this is helpful and if you have any questions please do not hesitate to e-mail or call.