We have 2 Shelf Trims in plastic, vintage items.  In the first photo on top:

This is from the 1950's.  It is plastic with an adhesive back (It is in the pkg. therefore I do not know if it is still sticky or not).  There are pleats throughout  the orange, brown and gold floral design.  The trim measures 7' x 1 5/8".  The pkg. it is in shows some wear especially on the edges. 

The bottom one with the red roses:This is from the 1950's. It is plastic and at one time had an adhesive back (the tape cover is still on most of it but it is no longer sticky). There are pleats throughout with a red tape separating the top from the bottom. It measures about 2 1/2 yards long x about 1 3/4" in width. The roses are gorgeous on this. Unfortunatly there is some blue "gunk" in 3 area's on either end of this trim. It comes off with your nail but leaves a blue shadow - I have not attempted to clean this. I don't want to mislead anyone - this defect shows in different degrees. There is 1 7/8 yards in between the above flaw which is clean. In my opinion this sounds worse than it appears.

2 Shelf Trims Plastic Vintage