Hoping this ongoing thread will save you a few bucks and a few minutes, here is my first summary.
CREATING A DESIGN WALL
The cheapest, easiest and most portable of all - felt yardage draped over a door, leaving a goodly overhang over the back ("inside the closet" face) so that it doesn't fall off when you open the door!
IF: (Low expense, low time = LET from here on in)
you have no closet door (I removed mine to insert a rolling sewing machine table)
Try using sheets of styrofoam duct-taped together (like the ones your kids made for science fair displays).
These can be folded if you hinge the panels correctly. I'm also told they can be put under beds - unfortunately that is my paintings storage space. Hmmm....continuing...
you want or are somehow restricted to a small sewing table quilt design board, just big enough for a quilt block or section, use a folded (think teepee rectangle of scrap cardboard trimmed and covered in felt or flannel (or a chunk of that camping picnic table cover, flipped over) with extra for the folding flange bit
IF: (HET = (you guessed it - high expense, high time) If you or someone near and dear to you is inclined towards woodworking, make "fake" doors or frames attached to the wall studs with sturdy hinges (here think poster or rug shop displays) making yourself a giant "quilt book". Nobody said you can't have a dream.
Time is your main constraint, but the bank balance is not,
just go out and purchase a ready-made design board and have it delivered to your doorstep. I guess this is the High Expense, Low Time or HELT version.
("Deep Peace of the Quiet Earth to You" - a small wall hanging I worked on recently)