.... The flour adheres to the backs and makes them "un-sticky".

Terry Reedy :

Corn start (or any starch) should work as well. It is finer than most
flours (which also are mostly starch).



Don and Terry,

Even better is to use talc (talcum powder ?). One may find it here in
France in drugstores.
I do not know if this is true elsewhere.

--
All the best,
Pierre Courtiade

to answer me, please replace NOSPAM by my family name