Miter Frames

Picture frames are complex. You would think it’s a simple 4 sticks glued together, and while true, there is just so much more to it.

We got a couple of paintings, and my wife wanted them framed. That means I had to do several floating frames for the paintings. I’ve done frames before, so that was a good fit, but I wanted to experiment with a new format - splined mitered frames.

I will not bore you with creating a mitered picture frame here. You start with the wood, mill it to size, miter - keeping in mind you have to be very well tuned with your tools to achieve the perfect 45 + 45 = 90 deg angle and close all four corners. That is a job in itself, and soon enough I had a frame that was being glued up.

Now I do know that endgrain glue ups are not structurally sound. That is very much true. At the same time - how much strength does a picture frame need really? I would argue - not much. You set it up, add content, and hang on the wall to sit still for years, decades even. Things might be different for standing frames, or frames that you take off often, but for majority of my use cases simple glue is fine.

I still wanted to see splines being added, for two main reasons. I wanted to know how much time and process it adds, and I wanted to see if the frame feels sturdier.

My approach was to build a simple jig with 45deg cutting slot, and run the frame through a lowered table saw on each corner. The jig ended up being 2 plywood offcuts with a tiny 4" mini clamp holding the frame to the jig. Once built, and after I ran the frame through the saw 4 times, I had cuts in the frame allowing me to glue in splines. I used some thin pieces of purpleheart in this oak frame.

This was simple enough and I let the glue cure overnight. Next day I trimmed the splines and sanded both the corners and the frame overall.

So was it all worth it in the end? In my case - probably not. While the frame felt sturdier, and I’m sure it would survive being dropped from a couple of feet much better, the additional time to prep, glue, wait for the glue to dry up and finish next day, adds quite a lot in batch production.

There are situations where I would go for splines still: if this is a gift and you want visual splash into the frame design, and/or this frame will be used heavily and you don’t want to do any mechanical fasteners in the back. For all other cases in my opinion a plain glued miter frame is plenty strong.