When I pre-bake a tart shell, I use beans but the sides of the shell still slump. How long should I chill she'll before baking? Other suggestions?

Also try freezing the shell before baking. You can pop the frozen shell lined and weighted right into the oven.

Thank you, had been lining with parchment and adding beans, will definitely try the foil.

Line the inside of the tart with aluminum foil, buttered (or otherwise greased) on the side that will contact the dough. The foil will support the vertical portions of the dough when it is hot but not yet baked. This slump-prone stage will happen no matter how long you chill the shell. I roll the shell out from dough as cold as I can handle and then re-chill it in the pan for 10 min or so, but this is to promote maximum flakiness.

That should read shell.