Help needed- mounting large(!) photograph

[Chris_Beagle]

Hi all, I don't often post, but always read the forum posts and have learned so much from you all over the years!

I have a client who has brought in a large photo print (110x77cm) that they want framed with a 1cm spacer so the glass is raised off the print. Ideally they don't want it dry mounted as it's fairly valuable, however my query is how to ensure that the print stays flat against the under-mount and doesn't 'bow' forward towards the glass. I guess even with dry mounting, large artworks on paper sometimes have a tendency to 'bow' outwards as time goes on. Does anyone have any advice as to how I could mitigate this?

Many thanks!

[Justintime]

I would be hinging it all around to a board cut to the same size as the print. The problem is that mountboard even 2.4 thickness can warp and cause the issues that you're aware of. I would look for an inert backing that doesn't have that issue like a polypropylene fluted board and hinge it to that.

[prospero]

I use this method with large paper-bourne art...

Forget card window mounts. If you need a visual effect of a mount then incorporate this into the frame in
the form of a wide panel. To serve as a window mount to let the art 'move' you need either a wide (30mm)
rebate - not always practical or would need woodworking kit such as a router table or the moulding may be too
narrow/awkward shape. A 30mm wide slip is the way to go. You can get these 'off the shelf' in gold or a raw wood
one which you can paint. These can be joined with a <5mm v-nail.

Hinge the art to a backboard. 5mm foamcore is good for large format prints.

Now the clever bit...

Run a 10mm strip of linen tape along to back edge of the slip. This effectively raises the slip imperceptibly but prevents
the edges of the print from being restricted. That leaves 20mm to cover the print edges less some clearance.

raisedslipmat001.jpg

* If you are painting the slip then you need another strip of linen tape to keep the glass from pressing on it or
you get weird 'Newton's Rings' effects.

[Chris_Beagle]

Thank you both for your advice- very helpful as always!