I am in the midst of looking to create a few Picture Frames, all varying in sizes. As such, I have been looking into what would be the best Width for the accompanying Rabbet.

From what I can see, 3/8" seems to be a common figure for Rabbet Depths regardless of the Width of the Frame.

Would I be right in thinking that using a relative figure instead, would be a more ideal scenario? For example 40% of a Frame's Width?

Am I overlooking something here or is it just a case that my thought process here is 'idealistic' in that a relative size would be ideal but the reality is that it would be unlikely to have a Router Bit to accommodate every relative size?

Apologies if this seems like an overly simplistic question but I am fairly new to Woodwork and would like to understand the 'theoretical' side prior to committing to the relevant Tools and Materials.

  • You should take some wood working Classes If you never did this. and work with all tools. Finish work is a art.
    – user101687
    Commented May 31, 2019 at 0:15
  • 1
    You might be pleased to know there is also a Woodworking.SE.
    – JPhi1618
    Commented May 31, 2019 at 3:42
  • @JPhi1618 ... Geat. Didn't even think to search for that. A there a way to get this question transferred over?
    – Craig
    Commented May 31, 2019 at 4:21
  • Question migration doesn't happen a lot, and the two sites have some overlap. This question isn't technically off topic here. I would just ask the question again on WW.SE after you search for similar questions, of course.
    – JPhi1618
    Commented May 31, 2019 at 4:24
  • Silly Rabbit, I think you are over thinking it a bit. The rabbet needs to be wide enough to support the glass and the substrate that the photo or art is mounted to and deep enough to accommodate the thickness of he photo or art is mounted to. A straight router bit used with an adjustable fence on a router table will give any options you want or a dado set on a table saw will do the same.
    – Alaska Man
    Commented May 31, 2019 at 17:11

1 Answer 1


Shifts in humidity will cause the frame to expand and contract across its width; the wider the frame the more it will expand. i.e. The wood total movement will be a small percentage the piece's overall size. So a four inch frame with a two inch rabbet will be much more likely to separate at the corners than a 2.375 inch frame with a 3/8" rabbet, despite them looking identical if the rabbet is covered by the frame contents.

Apropos larger cuts, shapers are larger than routers and spin knives rather than bits which allows them to do most of what can be done on a router table on a larger scale or in fewer passes. Large rabbets in a home shop would usually be done on the table saw or jointer though.

Using a dado stack on table saw you can take off just under an inch at a time. By moving the fence after each pass you can make a rabbet up to saw's ripping capacity. For shallower, wider rabbets you can cut them on most jointers up to the width of the cutter head. (6" at the smallest) So there are a variety of options for cutting rabbets beyond what your router does. [Technically you could hog off a huge on with multiple router passes, with sufficient time and patience.]

  • Thanks for highlighting the issue with expansion and contraction. Where I get a little lost, is within your examples in the first paragraph. You state that both of your examples would produce identical looking Frames. Are you including the overall Frame size, as my calculations do not produce the same dimensions? I guess I am just trying to understand the logic behind why a 4" Frame, with a Rabbet width 50% its Frame width, would increase the likelihood of the corners separating whereas a 2.375" Frame, with a 3/8" would not experience such an issue.
    – Craig
    Commented May 31, 2019 at 16:00

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