This is a link to a pretty good article on various laser materials. It starts off discussing a couple of new materials from Romark, including a laserable stencil material.
The article goes on to discuss different materials. Most of the information can be found in posts on this forum, but I think it is a great overview of the characteristics of common laser materials. Bear in mind that the article is from Engravers Journal and is geared toward production rather than crafting.
The author includes contact information on vendors, but it’s not really a sales pitch. More of just possible resources.