When I paint in pastel, I wear finger cots on the fingers that hold the pastel stick. Why? Two reasons. First, to make clean up easier. Second and, in my mind, more important, to keep my skin and nails from drying out. Painting in pastel has the same effect on your skin as digging in dirt. The pastel sucks both moisture and oil out of the skin. Skin will crack and bleed; nails will split.
For some artists, nitrile or latex gloves are the answer. I do use these when painting in oil in the studio, but they seem to get in the way when I paint in pastel. Outdoors, I sweat too much for gloves. A finger cot covers just the tip of your finger, down to the first or second joint.
For other artists, barrier creams work well. I find a cream messier than finger cots. Besides, it's an unnecessary bottle of liquid to take out when plein air painting, and I prefer the convenience of just keeping a Ziploc bag of finger cots in my pack.
I can also do finger-blending with finger cots, and this avoids the darkening that comes from getting skin oil into the pastel from the unprotected fingertip.
You can find finger cots in a local pharmacy or order them on-line.
