Digital BW, The Print

I've decided to try framing some prints without a cover matte.  These are Cone K7 grayscale prints that will have been dry mounted, with a Seal press, to archival (4-ply) matte board.  I've determined that the heating process does not adversely affect the Cone (carbon) inks.

To keep the print from contacting the glass, I'll need spacers around the edges.  I have no experience with these, so I'm looking for guidance.  I typically mount in 16"x20" frames.

If anyone can point me to a source that explains techniques, products and pitfalls, I'd be most appreciative.

Harry