These chairs are great. Comfortable. Easy to put together.  Very good price.  Will be putting some teak wood protector on them. They’re made with a polyester fabric called Textilene, apparently a pvc coated polyester, so I assume it’s pretty durable stuff.  We’re getting lots of pollen and tree junk down here in Florida right now and everything is easily wiped off that white fabric! 
My only gripe is that the highest set to sit the chair up is still too low to sit and have a drink comfortably.  It seems like it could be easily remedied by moving a few screws and moving the grooved base a  couple inches forward.  We’ll be attempting that soon, but it’s annoying to have to even be trying, hence the four stars.