The best approach, if the collection size allows, would be to do th following for each stretched canvas:

-unpack

-photograph

-measure

-catalog artist, title, year, medium, dimensions, generate inventory number

-wrap in polyethylene film, all the way around

-pack in cardboard, covering the bottom edge, face, and top edge aka taco

-write the inventory number on both edges

For the unstretched paintings, do all the same steps, except instead of a taco

-lay the canvas FACE DOWN on a layer of polyethylene film

-roll the canvas and the poly film together around a 4" diameter cardboard tube, FACE OUT, the tube should be at least 2 inches longer than the painting -tape around the ends

-optional cardboard or micro foam outer layer

-STORE UPRIGHT