I went with a cheap 3mm basic mat from the local big box to get started but quickly discovered that 3mm isn't enough for my trick knee at the moment. At the same time I didn't want something so think that it took away from the balancing postures. I am quickly learning that I need to feel the floor to balance and since balance is one of my challenges, I'm not going to put a 1/2 inch of foam between me and the floor.
The next size up at the local big box was a 5mm thick mat. The 3mm mat ran about ten dollars while the 5mm, sporting a whopping 2 more millimeters, was sixteen dollars and the same dimensions. From there, they went to 1/2 inch thick fitness mats that were actually shorter that the yoga mats for around twenty dollars.
So I was done with the big box.
I started looking online and almost immediately found 1/4 inch myMAT from Manduka and then spent some time staring at a ruler trying to decide if a 1/4 inch was too thick or too thin. But the price was right, the reviews were good and it was longer than the mat I had so I decided to take the chance.
So two days later (thank you, Amazon Prime), I had the mat and I got a first hand look at the thickness. Not too thick, not too thin. Probably just right. But it would take a couple of sessions at the studio to really test it.
A couple of the reviews on Amazon mentioned a chemical smell once you take it out of the package and I noticed it as well but after a wipe down with mild soap and water and the laying out for a day, the smell was gone. Even up close.
Now, I've had it for two classes, an energetic Beginner II class and a more rooted and pose heavy Intermediate/Advanced class. The new mat performed well in both. It stays where you put it and is just sticky enough to give you some footing without being so sticky you have to peel it off everytime you move. The 1/4 inch padding is just right between a hard surface and a sometimes tender knee without sacrificing the grounding effect of feeling the floor. I like the extra length (74 inches) although I could probably even use and extra inch or two but then I would be sucking up real estate in class so I think I can make do.
So for the money, it's a great mat for the level I'm at. I could spend a lot more money on a fancier mat (check the link to the store at the top of the page for some pricier selections) but I think this one could take me quite a ways into this new practice.
There are other colors available as well. Here's the link for shopping and parusal: 1/4 inch myMAT from Manduka