When you want to change the size of a canvas in Photoshop, you can do it in a few ways. You can use the Size command, or you can use the Canvas Size property. The Size property is located in the Properties panel of the Photoshop window. To set the canvas size, you need to enter two numbers, one for the width and one for the height. The first number is what is called your original canvas size. The second number is what you want to make the new canvas size. To set the canvas size using the Size command:

  1. Open Photoshop and click on its File menu and then select New Image.
  2. In the New Image dialog box, enter a name for your new image and click on OK.
  3. In Photoshop, click on its Tools palette and then select Canvas from its list of tools.
  4. Click on OK to close Photoshop’s Properties panel.
  5. In your new image, click on its thumbnail to see its current dimensions (width and height). The dimensions will be changed according to how much space was used for painting in your original image (width = 100%, height = 150%). If painting will not take place until after your new image has been created, then leave all other fields empty and click on OK when finished creating your image.