Make your own travel zafu

For zazen when traveling, a travel zafu is essential. The ideal travel zafu is light, collapsable, and does not take up much space in your luggage. It is not too difficult to make your own travel zafu, which is basically a zafu cover willed with an a partially inflated beach ball.  Sewing instructions for a zafu cover can be found here.  It takes about 3-4 hours, depending on how good you are with a sewing machine, and longer if you sew by hand.  You may want to consider a sturdy fabric, as outdoor zazen while traveling can be very inspiring, and the covers can get dirty.  A supply of beachballs can be ordered from various sources, and I find that the 20" size works pretty well.  Remember, the beachball will only be partially inflated.  I have tried a few things for a travel zabutan, but they are all bulky, such as yoga mats or air matresses.  If you have any suggestions, please contribute!