Frame width

[countrystudio]

On a glass size of width x 745mm height what is the minimum width Oak moulding that can safely be used.
Rebate depth 25mm
Client wants the frame as narrow as possible but can they have what they want?

[prospero]

As narrow as you want if you use a subframe.

[countrystudio]

Thank you. Client wants to use a deep rebate moulding with a spacer to recess the artwork.
I would like to use a 30mm wide moulding but was wondering whether I could use a 15mm instead. Hence the (silly?) question.

[Kwik Picture Framing]

There are no silly questions on this forum, just those we need a little help with. I can't believe how many useful tips I've picked up in the short time that I've been a member.

In answer to the original question (leaving aside the subject of a sub-frame) I've done a frame to that spec at 15mm width without any problem.

[prospero]

If you start with a subframe as the main support and fix everything bar the frame to it - sandwich the whole lot with tape right onto the glass, in theory you can hang it on the wall without a frame at all. Wouldn't recommend doing that for long as the tape will give but the principle is sound(ish) The frame in this case only serves to hold the inner sandwich together, a task that even tiny mouldings are more than adequate for - providing they are deep enough.
Good straight timber for the subframe can be quite hard to find though. One method I use is to get some thin tongue and groove cladding. It's cheap as chips but only about 8mm thick. can be a bit curly but that don't matter as what I do is laminate it. Takes seconds to glue 'n' screw together. Another advantage is that you can easily form a half-lap joint on the corners this way. Much stronger than a mitre. Once made you can be reasonably sure that it's going to stay put and not twist. You can also form a little pocket to take a wall cleat for flush mounting to the wall. Great for mirrors. One drawback is that you really need to rip off the tongue side. The groove doesn't matter so much. You can get nice PSE stripwood which would be ideal for this purpose, but some of it is more expensive than a typical high-end moulding. I suppose if you intended to do this regularly then a timber yard could run you up a quantity at the right price.

Another tip: Don't make the subframe too snug in the outer frame and don't fix it too firmly. There is the danger of the stronger subframe expanding and cracking the thin outer frame corner(s). Like on my bathroom mirror.

[Roboframer]

a glass size of width x 745mm height

What's the width?

If it was the same or less than that height then it's not that big so why get in to sub frames? Just choose the narrowest that is fit for purpose without one! So of course the customer can have what they want, it'll be the narrowest possible, it just won't be the narrowest available.

[prospero]

Another way is to use a good solid back (2.5mm MDF or Hardboard) and rivet a couple of double d-rings to the back. You have to be careful to well isolate the tails of the rivets from the back of the artwork as they can rust. It does make quite a strong fitting, but not anything over about 36x24".
OK for cheapo posters but not recommended for anything remotely valuable.