3M brand 48mm self adhesive paper tape is a quality product for sealing off the  backs of frames in the picture framing industry.
With a little firm pressure on both frame and backing board the tape bonds instantly and holds extremely well under all humidity conditions.

Generally used on frames that have a width of 50 to 100mm.

Note: when using tapes, you do not need to cover the complete back of the frame with tape, approx half on the frame and half on the backing is fine.

Comes in a 55m roll