For an ESD mat that can take the heat of solder (i.e. what Dave has on his bench), is rubber (NBR or Nitrile Rubber) and ideally what you want (typically 2 layer products, but sometimes 3). It resists heat, chemicals, abrasion, cut resistant, and will offer surface protection for the surface beneath it (not as soft as vinyl for example, but will take impacts). Has some grip to it, but not as much as silicone. Colors for this stuff are usually limited to one or two shades of blue (blue and/or light blue), grey, and green (to indicate lead-free). 3M and Sierra are rather common brands for these (get the kit, as it includes the grounding plugs and the mat will be fitted with a snap connector rather than buying a roll). Unfortunately, its not exactly cheap.
Silicone can be had cheaply, but isn't ESD rated (baking mats or place mats for example). Projects won't really be able to slide around on it either. Colors can be pretty much anything.
Vinyl, ESD rated or otherwise, will melt when exposed to solder.