Helen wrote:

I wanted to put a mat/frame around a photo, so I went to "canvas size" and enlarged
the canvas, thinking I could fill the extra space with color. Turns out I can't do anything with that extra space -- can't paint on it, can't even access it.

I know Layer|Layer to Image size works. The current background colour is used.

--
Bob Long

Helen wrote:

I wanted to put a mat/frame around a photo, so I went to "canvas size" and enlarged
the canvas, thinking I could fill the extra space with color. Turns out I can't do anything with that extra space -- can't paint on it, can't even access it.
Is this normal, or am I doing something wrong? (Yes, I know I can go to script>add border,
but I just thought I would try something different.) What's the purpose of this extra canvas
space if it can't be accessed?
Thanks, as always,
Helen

Hi

Keep in mind that you are never painting on the canvas itself, but on layers. Changing the canvas size does not change any layer sizes. You can toggle layer boundary visibility in View -> Show Layer Boundary. To change layer sizes you can use for example the Crop Tool (with some changes its tool options) or the various layer size related operations accessible under the Layer image menu.

Best regards, Martin Nordholts

Helen schreef:

I wanted to put a mat/frame around a photo, so I went to "canvas size" and enlarged
the canvas, thinking I could fill the extra space with color. Turns out I can't do anything with that extra space -- can't paint on it, can't even access it.
Is this normal, or am I doing something wrong? (Yes, I know I can go to script>add border,
but I just thought I would try something different.) What's the purpose of this extra canvas
space if it can't be accessed?

As Bob and Martin write you can adjust the size of the existing layer to the new canvas size, but I think in cases like this it's often easier to add a new layer and put it behind the photo layer. Then you can work on the new layer to make a border without risking to change the photo.