As noted in a previous response, boules can be placed in floured bannetons or brotforms, then placed in a small plastic bag and retarded overnight in the refrigerator.  If you don't have a banneton or brotform, then use a high quality linen cloth, flour it thoroughly, and use a small colander as a makeshift banneton.

Batards are placed on a narrow strip of parchment, then moved to a couche on a baking sheet.  The baking sheet goes into a big plastic bag and into the refrigerator.

Plastic bags are reusable and your dough will not dry out nor will it be oily.  Try it!  It works!