A few days ago, I visited my mother and stayed overnight at her house. I didn't bring a yoga mat (I own three) because I recalled she had an exercise mat tucked away underneath my childhood bed. After using that exercise mat which was not designed for yoga but for other types of stetches and perhaps calisthentics, I definitely realized you actually do need a yoga mat for your yoga practice. My mother's mat is made of urethane foam and while it provides cushioning, it doesn't help you avoid slipping and sliding when you do certain poses!
Fortunately, nowadays, outfitting your home studio with the right type of yoga mat is very easy. The myriad types of yoga mats of all colors and designs and materials that you can choose from is almost dizzying. All you have to do is flip through magazines such as Yoga Journal, search online or get catalogs from companies such as Gaiam or Barefoot Yoga.
Most yoga mats are rectangular (although you can also find some newer circular yoga mats that are 4 to 8 feet in diameter and designed to allower freer and more fluid range of movements - at least for certain poses) and most range in length from 68 inches to 75 inches. I am a "shortie" and so the standard 68 inch mat suits me fine, but if you are tall, be sure to buy a long enough mat. Most yoga mats range in thickness from 1/16 inch to 1/4 inch. The thicker mats clearly provide more cushioning, but also are heavier and bulkier to roll up.
I bought my first yoga mat about 4 years ago when I took a yoga class at my Federal agency. The young lady in charge of registering class participants bought a bunch of mats for us at Marshalls. They only cost about $15. The problem with inexpensive mats, however, is they are the least environmentally friendly because they are usually made from materials such as PVCs (don't know what that stands for) that initially emit unpleasant, toxic odors at least the first few times you use them. I actually didn't have this problem with the Marshalls mat but I definitely noticed an unpleasant odor with another mat I bought from a catalog. The next mat I buy will be made from thermal plastic elastomer which is more environmentally friendly and recyclable or I will buy one made from natural latex or organic natural latex. Yoga mats can range in price from the $15 inexpensive type to over $100 depending on the material. I think your standard mat will run you between $30-$60.
You can also buy "mini" yoga mats - that is, grippy yoga "toe sox" to put on your feet and yoga "paws" for your hands that reportedly allow you to practice on any surface. However, in my view, they don't offer cushioning which is most important to me for those supine poses. In short, although I did yoga for years without a mat, I have learned that a yoga mat enhances your practice and provides your body with protection. Invest in one for your home studio.
Laura's corny Wisdom of the Day: ~"Your yoga mat is where it's at!"