I have used most traditional surfaces to paint on over the years. Currently I use masonite wood panels, for several reasons. It is light and can be cut to size for any frame. This is important, as I frame all my paintings, and a lot of frames are old and have odd sizes. Weight is crucial, as I have to carry bins of paintings to and from art fairs.
Masonite has no texture, it is very smooth. When I used canvas, I never liked the threads that people associate with traditional paintings. I remember at one art fair I saw some paintings that had some kind of added texture, that made it look old, and enhanced the color. The texture pattern seemed random. I asked the artist, and he said it was like a plaster that is applied to the canvas or panel first. I ended up buying and trying some 'Liquitex Lightweight Modeling Paste', and like it a lot. More than several customers commented that they liked it too. It was easier to use on large surfaces, so on Cold Light I haven't used it, as these are much smaller paintings on average.
I have seen paintings on glass and metal I like, but there are complications that have prevented me from using these. Other surfaces I am wary about trying, I have heard stories about paintings that peel or bubble on nontraditional surfaces.