I guess I need to emphasize the absolute necessity of skirting fleeces. I have recently noticed that when I ask if the fiber has been skirted, I'm given an emphatic "yes". However, when I open the bags to look at the fiber, it is apparent that the skirting is not at the level needed.
Let me first explain the reason for skirting. It's to get rid of everything you don't want in your finished fiber/yarn. Any hand spinner can tell you that it's not a pleasant experience to try to spin fiber that has vegetable matter (vm) is it. It's rough on the hands, and can make the finished yarns look lumpy and feel prickly.
So the things you want to get rid of are: vm and short fibers (fibers from second passes by the shearer and/or fibers generally under 3 inches). Fibers that are between 1.5 - 3 inches are wonderful for rovings, but anything shorter can end up making neps on processing machines.
When I skirt my own fleeces, it can take me typically between 5 & 10 hours (I'm really picky). I look at the tip side of the fleece and removed large pieces of vm, then I flip it over and brush my hands over the cut side. This will often dislodge the "shorts" and I remove as many as possible. It gets flipped back over and I take each lock or group of locks and remove as much of the larger vm as possible (some of it will fall out during washing and processing, but not all). I check the cut end of the locks, tugging on them to make sure that there are no short fibers sticking to them. Is it time consuming? Yes. Do I get beautiful results from the extra effort? YES!
So before you bring your fiber to a processor, think about the end-result you want. Are you ok with some slubs and vm? If not, help out your fiber mill and remove as much of the unwanted material as possible. You will both be happy with the results. Have a wonderful first week of November!