Felt serves other purposes than as a covering for the ger. It is also embroidered ornately with a technique called shirekh, using thread made from camel wool, to make olbog or cushions and uud or the felt door for a ger. Usually, nevtgelzekh or "sewing with a forward stitch" is used for felt stitching. Stitches have to start from the centre of the ornament, so that the felt doesn't move. The stitching thread is not tied in a knot, but is instead quilted into the felt. Stitching distances must be equal and also close to each other. When the stitches are made appropriately and meticulously, the top and bottom sides of the felt look the same. Felt-stitching has different styles according to the practices of the many ethnic groups of Mongolia.