I'd like to address some of the negative comments I saw before deciding to purchase this mat. I will say that I don't intend on using it for cutting persey, but it does look awesome on my desk and protects the glass from scratches and all-too-common smudges.

First of all, there was absolutely no odor when I removed the mat from the box and took the cellophane off. I was pleasently surprised by this, as I thought I would need to let it air-dry for a while before keeping it on my desk.

Second, the mat came perfectly flat, in a flat box, not rolled and not bent as some other reviews have suggested.

Third, the angle markings are in fact accurate. I measured each angle and they all checked out.

The quality is great, the mat is sturdy and durable. It gives my desk a nice 'technical' appearance that somehow makes me feel more productive and work oriented while I'm sitting down at the desk. I purchased the 36"x24" version and it fits exactly as expected. Would recommend!

Excellent for protecting my desk. The mat has a nice solid feel, with crisp white text on the black surface. This is definitely a great addition to my work station. I have the 36"x24". The actual measurements printed are 34"x22" with 2" of space around the edges. Does have a slight smell fresh out of the package, which dies down after airing out for a bit. I'm happy with it so far!

I use this mostly for general dent protection on my desk; but I do cut materials on it. I have an Alvin Alvin GBM2436 GBM Series 24 inches x 36 inches Green/Black Professional Self-Healing Cutting Mat for comparison. Both are essentially identical in terms of build material and performance; they seem to react to cuts the same way. Grids on both are accurate. You can't go wrong with either one.

Shipped curled in half (arrgggh), but it flattened out fine in 20 minutes w/ some weight on it.

For the self-healing: don't expect miracles; they aren't magic. They will start to show heavy cuts over time. Use sharp blades, not brute force. Blades are cheap and it's not worth fighting a dull blade.

Head to head with the Alvin (top of pic is the Dahle, bottom is the Alvin)
The Dahle Vantage markings are bright white, quite a bit easier to see than the Alvin.
The Dahle does not have markings on the opposite side; it's just a solid color. The Alvin has the same grid on both sides.
The Dahle is 0.125" thick; the Alvin is thinner at 0.104" (what can i say? I had a set of calipers at my desk)
The Dahle's centimeter markings are nice, but limited usefulness. Wish they printed both Inch and CM numbers the entire perimeter

This mat is simply amazing. It's sturdy and smooth, and fabrics cut like butter on it. Cuts disappear like they weren't even there. It smelled a bit like PVC when I first opened it, but that's expected. A day airing out the smell got rid of it.

Some other reviews complained about the mat sizing, but it's exactly as described in the listing: the actual SURFACE AREA of the mat is 12 x 18 inches, and the rulers printed on the mat are 17 x 11 inches, with a centimeter ruler on the opposite corner.

The mat also shipped flat, which is a plus! It's 1/8 inches thick, and is a pleasant blue color, which makes it easy to find under any fabric stash. I would recommend this Dahle cutting mat to anyone who sews or works with anything that needs to be cut with a rotary cutter!

Ive had this mat about a year and a half and while its nothing super special it has held up reasonably well over that time. I use the mat for cutting a few times a week and it typically stays as a work surface on my desk in between cutting uses.
This particular mat is susceptible to heat, as in a bowl of soup or a mug of coffee. Over time this will put small warps into the mat and eventually that makes it more difficult to use for precision cutting.
I attempted a "fix" for the small warps, placing it in the oven on a low temperature for a while, and it worked! The mat came out flat as a pancake, however it also shrunk significantly in the process. What was once 18x12 is now 17 1/4x 11 7/8
If it had shrunk proportinonally this would be much of an issue, but since Its no longer square and true Im ordering another which I intend to take better care of!