On 15.07.13 at 05:37 AM billlee wrote:

What am I doing wrong or missing??

The problem is that with the default settings there's no layer area in that newly created, free space.

The easiest way is to 1. Go back before the Image/Canvas Size... step, 2. set the color you want to have in your horizontal space (for instance white) as background color,
3. in Image/Canvas Size..., listbox 'Resize layers' choose 'All layers'. I assumed you have only one layer. Otherwise another option except 'None' would be appropriate.
You save the Bucket Fill step to achieve the same and in future you can start with step 2.

4. Optional: If you want to fill your space with a gradient or similar use the Rectangle Select Tool or Fuzzy select tool, select the space and fill the selection according to your needs.

Kind regards,

Sven

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On Mon, 15 Jul 2013 05:37:17 +0200 billlee wrote:

GIMP 2.8.6 on Window 8.

I used Canvas Size to add a horizontal space at the bottom of a jpeg photo. (I want to use it for a text caption for the photo.) The new space is filled with a checkerboard of small light & dark grey squares.

I used the Rectangle Select Tool to select the new space.

I clicked on the Bucket Fill Tool and moved the mouse over the new space. The mouse pointer includes a circle with a diagonal stroke through it, indicating I cannot fill the selected area.

What am I doing wrong or missing?? (Probably something simple--I'm a GIMP newbie....)

Many thanks!! Bill

Hi Bill.
You see the checkerboard because the layer is set as a transparency (without color). After enlarging the canvas, try creating a new layer with the background color you wish then position it at the bottom of the enlarged canvas.

Tom

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