The Framers Forum

Hi Guys hope you can help little me

Ok even though I've been framing for a few years, never had to do this as yet:

Deep box frame with float mounted print with no window mount, but also with no edge border,
so i'm wondering what is the minimum gap in your opinions between the edge of the paper and the wooden spacer for expansion. Don't really want the edges of the paper to be obviously visible

or is that going to look weird once all framed up?

Am I right in thinking that wooden spacers shouldn't pin the paper around the edges??

Thanks in Advance
Dan

OK. Think I know what your're driving at.

It depends on the paper as to how much it will expand. It may also shrink. A 30" sheet of medium watercolour paper will grow a good 1/2" when it's wringing wet. So the answer it probably "more than you think". The bigger the sheet, the more elbow room it will need, but a min of 3mm all round I'd say.

The problem is that the typical rebate lip width is round about 7mm. The spacer needs to be about >5mm to support the glass properly. That doesn't leave a lot of room to play with. So you would really need to widen the rebate width or add a slip.

we have done some experimentation with paper expansion, as Prospero says it can grow a lot! the most alarming was a A3 sheet of fibre based photo paper 280 gsm which grew 3 mm from being cold to being at room temperature, this is why we opted to keep our work and store rooms heated to normal room temperature.

Thanks guys

Ah yes 3mm is what I had in mind - they are only small prints so should be fine

thanks again

3mm.

Btw it's not just expansion that you need to watch out for, it can shrink, too.