Thought I'd chime in with a few questions/thoughts on the deskmats.
1) This is just a personal thing, but I think your first design is very "busy" and quite visually cluttered. I've spent a while looking at it and I think cutting down on the amount of stroked/outlined shapes could reduce that visual noise and make for a more appealing design. (This is just a personal thought though)
2) I've designed/prototyped my own deskmat designs in the past and one of the things I notice here is that some of your lines are VERY thin. This may not translate to print as accurately as you might like, and they could potentially either look blurry or too faint. This is something I'd check with your manufacturer or vendor if you decide to put this into GB.
3) Your black background is VERY black. I don't think I've ever seen a dyed cloth-like material to ever achieve that level of black printing, so I would possibly adjust your design to accommodate a more real-world look, as that what your designs should showcase. Take a look at some other popular deskmat designs with very dark base colours for references.
4) Finally, this could be a big assumption from me so I apologize in advance if it is, but just due to the limited number of posts on your account here I'm curious if you have these designs created in vector format + CMYK colourspace? If you have, awesome, but if not it's something you'll definitely need to do sooner rather than later to save yourself the headache down the road. Another thing is to ensure a sufficient bleed area on your design for printing so that you don't run into prototype issues if the printing margins/alignment is slightly less than a typical 900x400 canvas.
All in all, best of luck with your design!