Photo credit: O'Ryan Empire Photography
Step 1: Choose your canvas size
For this guide I will be cropping my image to print as a 12"x18" gallery wrapped canvas. This means that my final canvas size will be exactly 12x18, but I will need to account for the wrapping of the canvas around the frame.
To do this I need to prepare my canvas with an additional 2" border on every side. The 2" is to account for the 1.5" on the side, and .5" where the canvas will wrap around the back to be stapled so the staples are not visible.
The best way to do this is to crop your image larger than your canvas size by adding 4" to each dimension. For a 12x18 canvas you will want to crop your image to 16"x22". This is the same process you will use for every canvas size.
Step 2: Crop your Image
Keep in mind when arranging your crop tool that you will be losing 2" on every side so try to allow for that additional space.
Step 3: Drag your ruler in 2" from every side and check your final file size
The 2" outside the blue ruler guides show the area that will be wrapped around the sides and back of the canvas frame. Please note that 1.5" of this will show on the edge of the actual frame and 0.5" of it will be wrapped onto the back of the frame. The area inside the blue ruler guides is what will show on the front of the final wrapped canvas.