The Framers Forum

I have some large (around 1m squareish) pieces to frame in a narrow moulding.

The pieces are paper collages mounted on 12mm ply and will be unglazed. I was going to use canvas offsets to hold the piece in place to mitigate bowing/warping but am wondering whether there is any benefit to adding batons around the edges of the ply to attach D rings (big ones) to, or whether I can just attach them directly to the plywood on the back?

Would the additional strain on the plywood exacerbate warping if D rings are attached directly?

Do it like a wall mounted headboard.

So, yes, make a frame to edge the plywood and then make cleats from the same thickness wood as that frame (if you use a wide enough batten, use the exact same stuff), this will put the frame perfectly flush to the wall.

The top batten could be the cleat but it’s best to put it about a third of the way down …. just like a headboard.

Zac,
#1
plywood is not an appropriate support backing material for paper art due to the chemical properties of this construction material. A proper art product should be used.
#2
Why does the client want to omit the use of a glazing as a protection from all airborne contamination? The unprotected paper based art will absorb all sorts of nasty pollution; thus reducing the useful life of it.

Regarding the mounting of the art to the plywood.... Are you saying that the art is just suspended onto the board without any hinges and or adhesives? With no glazing in front of the art there will be additional stress on it with just edge clamping. Humidity changes will be more severe than if it is in a basic closed frame(not a hermetically sealed frame).

As a picture framer we have to pay attention to several of the natural sciences, chemistry, physics, mechanics.

Thanks for the advice so far :c)

I've discussed the suitability of using plywood as a backing, and the disadvantages of leaving the pieces unglazed extensively with the artist and they are fully aware of the issues, the method they've gone with is their choice.

They decided to bond their artwork to the ply with PVA, sizing it first with a thinned down coat, and have varnished the paper to give some protection against the elements.

They also don't particularly want the "headboard" option :c_(Though I did posit this as French Cleats) as the pieces will be displayed in Open Houses before hopefully selling on, so simplicity in hanging is key.

So really I'm just wondering whether attaching the D rings to the body of the plywood will put more stress on it than attaching to batons fixed around the edges.

Perhaps use hanging straps instead.
That way there are more screw fixing points and 12mm ply is pretty substantial so you should be OK.

OK, use hangings for cord/wire but still brace the board - I’d use batters made from plywood at least as thick - I don’t think 12mm ply will stay flat over time otherwise, maybe it still won’t- 18mm would be better.

Still fix a cleat in place (which will add even more strength) and attach the wall cleat to it so the end user can decide. The cleat on the board should be the full width and the one for the wall, not.
Panels like this look much better flush to the wall.

The board should be sealed on both sides and the edges too. If then a few coats of gesso were applied and sanded - it could be painted on directly and then given a protective layer of acrylic medium.

Excellent, thanks for the advice :c)

With plywood being a home/industrial construction material, I am sure that it has more than enough strength to be supported with D-ring hangers depending on the number of screws( 2 or more per hanger) and their sizes.
Plywood sheathing is used all the time to support electrical and plumbing panels to walls.