Float mount and archival backings

Hey all, just a simple question..

I'm float mounting a couple prints for a coming show. My plan is to dry mount the print to an acid free rag board as a pedestal, then attach that board to the backing with linen tape.

Does the backing need to be archival since it's not making contact with the print? The acid free foam boards have a slight yellow hue to them that I don't like since it will be partially showing. Is there any down side to using standard white foam board?

Thanks!
Chris

If you were not dry mounting your print to the rag board, I would say no, the backing does not need to be archival.

Since you are permanently attaching your artwork to the rag board the rag board is now artwork and you do not want the artwork in contact with non archival materials.

Granted, it will take a while so it depends on how long you want it to last. Many of Ansel's prints are dry-mounted and I can assure you no gallery is going to put his print against regular foam board.

An option is to use 2-Ply rag board in between the mounted print and the foamcore to act as a buffered layer that can be changed out over time as it gets contaminated. Not only will it get contaminated from the foamcore but from the wall you hang it against and from pollutants in the air.

Cheers,
Mark