Is the lignin in wood frames a concern?

[walbergb]

I make my own wood frames, usually out of maple. I don't usually stain and top coat the rabbet cut. Should I be concerned about the lignin from the raw wood adversely affecting the overmat?

[Paul Goutiere]

Any time the mat touches wood you can have a chemical change. The glass will prevent contact, assuming you intend to use glass or plexi.

[BMbikerider]

A coat of varnish inside the rebate and the back edge will also make it sealed.

[DREW WILEY]

Never use conventional varnish unless its been thoroughly outgassed over a period of six months or
more. The solvent fumes aren't good for the print; and water-based versions might not consitiute a suitable barrier layer. What you want to use it true shellac, the alcohol-soluble kind. It is a unique product which can't be synthetically duplicated. You could also apply foil tape to the rabbet, but
shellac is simpler.

[fdi]

Wood is a naturally acidic product. Most people are aware in the protective use of the mat in keeping the print off the glass, but it is also useful for keeping the print away from the rabbet of a wood frame. Lineco makes a frame sealing tape.

[Bob Carnie]

+ 1 on the frame sealing tape

Wood is a naturally acidic product. Most people are aware in the protective use of the mat in keeping the print off the glass, but it is also useful for keeping the print away from the rabbet of a wood frame. Lineco makes a frame sealing tape.

[walbergb]

Thanks everyone. Frame seal tape sounds good

[thefizz]

Interesting info.

[RalphLambrecht]

yes, stay away from wood and go for anodized(not painted)aluminum.

[Paul Goutiere]

Conservators will use foil (aluminum) duct tape for the inside of the rabbet which is inexpensive and really easy to find at most hardware stores. It is a tad
hard to install because the aluminum can tear easily.

Better yet is material like some stuff from "LINECO" called "I-Film Frame Sealing tape". It is archival and easier to install in the rabbet.