On that note, (how's that for a segue?) here's a little about paint media for oils. For starters, when the quick drying alkyd paint came out, I bought a set. It didn't take long to realize that using the medium only-Winsor Newton calls theirs Liquin-with regular oils accomplishes the same drying speed. Without the concern of the paint drying in the tube. Duh. Alkyd resin is available as a gel also under different trade names. It also contains dryers, sometimes silica for body. I don't particularly like the surface buildup, for lack of a better word, so I cut it with mineral spirits. A so called "magic" medium such as Marogers contains many additives along with mastic varnish . Trust me, it won't make you paint like Rembrandt.
SELF PORTRAIT Rembrandt
Pretty impressive drawing, yes? Especially considering that the original is the size of a postage stamp.
Blockx, which makes an exceptionally high quality paint, also makes an "Amber Medium", a resin that lays claim to"transparency and radiance" etc etc. I'll never know, because a 50 ml bottle is $441 list. So Keep It Simple. Skip the dryers, they can lead to cracking. You don't need turpentine. Don't use unrefined hardware store linseed oil.
A good practice is to start your painting with rapid drying paint: Burnt Umber, Raw Umber, Burnt Sienna, Pthalo Blue, Pthalo Green, Flake White (aka Lead or Cremnitz White) and a rapid drying medium: 6 parts mineral spirits, 2 parts sun-thickened linseed oil, and 1 part dammar varnish. Slow drying paints and medium are: Any of the Cadmiums, Ivory Black, Lamp Black, Vermillion, and Zinc White. All other colors fall in between.
If anyone has anything to add or correct, feel free, I'd like to know. Also, the finished Keith Richards painting, and The Redhead, have been added to my website.