Soils are heavy and cause the fleece to shrink- more than corral dust which is mostly vegetable matter. Learning to estimate yield will take much practice, so do not give up if you are having trouble. This includes crimp, handle, and color. Crimp is the natural waviness of the fibers. Crimp Is important for breed character and is indicative of wool grade.
Fine wool has the most crimp per inch while common and braid have the least.
Many people associate crimp with grade but it is only an indication of grade. Handle refers to the feel of the wool. Rule of thumb is that a soft fleece makes a soft fabric and is worth more. Color is very important, primarily for accurate dyeing of wool. The most desirable wool to dye is white.