Modern yoga blocks are made from a variety of materials. The most common blocks are made of foam, but cork and some wood may also be used. The ideal block size, according to B.K.S Iyengar, is 9 x 4.5. x 3 inches. This is still the most common size, but there are other options available. This allows yogis to customize their yoga practice in a way that best suits them.
While yogis have traditionally used various props for centuries, the use of yoga blocks first became popularized by Iyengar yoga in the late 20th century. Iyengar yoga emphasizes proper alignment, and yoga blocks are an excellent tool to help achieve this.
Yoga blocks can be used by yogis of all levels. Beginners often find yoga blocks to be useful as they help modify challenging poses making them more readily accessible. More advanced yogis can benefit from the deeper stretch they are able to gain. For certain asanas, yogis can use multiple blocks to support their alignment such as during splits.