I have sent numerous fibers to my local mill to be processed into rovings and felt. I rarely have anything done that hasnít been blended for any number of reasons. Angora with merino will make a yarn with a halo and luxurious softness without being so expensive that no one can afford it. Alpaca blended with Shetland is one of my top selling combinations because the two varieties have a very similar lock length and the wool adds loft to the alpaca. But how do you decide what fibers to put together, and what proportions work best? It is through trial and error for the most part, but to reduce the error side of the equation, it certainly helps to audition your blends.
Begin by washing any grease wool that you plan to include in the blend. You do not need to wash the entire fleece, just a few locks to give an accurate representation of the color and texture of the wool. Any raw mohair will also require a few pre-washed locks to determine the blend. Camelid fibers and angora do not have grease, so just be sure they are relatively clean before you begin.
The next step is to dye any of the fiber that you plan to dye for color blending. This is a whole different subject, but a word to the wise, double check any dyed fiber that you intend to send to the mill to be sure the dye is set properly. Nobody wants to be the one to hold up production at the fiber mill.
Start the audition by laying locks out with the fibers parallel. Weigh each fiber type and write the weight on an index card before adding it to the blend. The fibers can be blended by fluffing them open with your flick card or on a lap board and layering them together. Grasp the resulting bundle of fiber at both ends and tug it apart until you have about half in each hand. Lay the two halves back together and repeat the process until the blend is uniform.
Continue testing the blend by spinning it either with a wheel, spindle, or by simply twisting it between your fingers. Once it is spun into a single thickness, draw it off of the bobbin or spindle and allow it to double back upon itself. This will give you a good idea of what the finished yarn will look like. From there, if you are pleased with the results, you can tape your yarn sample to the index card and send it along with the fiber to the mill. If the blend is not what you hoped for, you are in luck! You can try again with a different proportion of fibers, or change fleeces without incurring a mill bill for something that is not quite what you hoped for.