Sleepbetter.org was doing an interview on TV news. They said that you really can't get a thread count for sheets that is more than 500. If advertised as 1000 thread count, it's 2 sheets woven together. I thought that was interesting.
That web site is supposed to have info on finding the best pillow for your needs. I haven't checked.
Source: http://www.sleepbetter.org
By Holly from Richardson, TX