I paint with vinyl paint on silk-screened paper. Both are densely pigmented and have a velvety matte finish. The paint dries almost instantly and I use very small brushes that require a repetitive cumulative application that is meditative. The scale is determined by the availability of the paper.
I made a conscious effort to make the work sustainable in the sense that I don't need an elaborate setup to work. Water-based means no fumes, and it’s on paper so I can stack a whole year's worth of paintings in a folder.