patriarch wrote in message . 16...

It takes a standard router table and fence to do this safely, in my
opinion.

I do it without. It certainly needs a jig, but given the size of
picture frames, I'm happier about clamping the jig to the frame and
using that as the guide than I am trying to feed a frame through my
table, whilst resting one corner on a sliding jig.

My jig is simply a triangle of MDF with two guide bars underneath and
a couple of stopped slots in the top for the cutter. I clamp it to the
outside of the frame, butted against the bars, and slide my router
along another bar on the top at 45 degrees. There are two slots, to
permit different frame stock widths (there's a bar either side, which
also makes it a very solid jig). Mine is dedicated to one router and
one baseplate size, but you could easily make it to run against the
edge with a router fence, rather than fit the guide bars.

For making the key stock, I just use a block plane. I'd probably make
up batches on the router table (many frames' worth) if I did this
regularly, but it's an easy enough task to hand-plane them from a
strip. It's only a short length, so keeping the size accurate over
that distance isn't too difficult.