Resizing and Adding to an image

[denzjos]

I do it this way : on the Gimp menu :
- Image / Canvas Size
- Fill in the size 'With' and 'Height'
- Resize layers : choose 'All layers'
- Fill with : you can select 'white' or 'background color (if it's white)
- Offset : fill in 'Offsets' or move the canvas by using the mouse