Size
The size of the L pad is similar to that of many other large pads, like the Qck+/Heavy or Zowie G-SR, as it comes in at 450 mm x 400 mm x 3 mm.
Below is a picture of the pad fresh out of the box. There are still some waves to the material due to it having been rolled up for such a long time.
The XL version is a deskpad with a size of 450 mm x 800 mm x 3 mm.
To get a better understanding of the size of these pads, I included pictures of both below, with a DM1 Pro S for a size comparison right next to and on top of it.
Personally, I would prefer the XL to be even bigger, like 1000 mm wide, so that I could fit my whole keyboard on it and still have the same area available for my mouse as with a DM PAD L next to the keyboard.
Material
The top has a a soft cloth microfiber material that is similar to that of a Zowie G-SR Black, though it is a bit rougher. It's a bit more silky than that of the Steelseries Qck, the probably most well-known example. The backing is a non-slip rubber. The rubber backing is very good, grips my wooden desk adequately, and does not seem to have any air bubbles in it. It's not as soft as the G-SR's backing, but at least on par with the regular Qck Heavy's and far better than that of the Puretrack Talent. As you can also see, the mouse pad's edges are stitched, keeping the surface from fraying, which happens with unstitched edges eventually as you use them.