How I do make customised photos in Photoshop?

Our software always enlarges the long side proportionally to the print’s short side. And with a panoramic shot, to the print’s long side. So, one of the sides will always be ‘standard’. But, what if you want an entirely different format, e.g. a printing format such as A4?

We will explain step-by-step how you can do this. Let’s begin:

Trimming

• Start by trimming (shortcut key C), select “aspect ratio” at the top and then enter your preferred aspect ratio, e.g. 29.7×21 (do not include measurement units such as cm or mm)

Edit the image size

• Go to Image-> Image size (shortcut key Alt+Ctrl+l) -> and enter your preferred size -> OK. 
• This relates to the same aspect ratio you entered previously. Make sure the ‘calculate new pixels’ tick box isn’t ticked. If you don’t tick this, the resolution automatically changes with it.

Determine the measurements the photo fits into.

• One side is fixed; the width of the paper roll your photo will be exposed on to. With all formats this is the short side, except with 10×15 up to 11×15, when it’s the long side.
• The fixed side will NOT be trimmed. The other side is trimmed at the point where the photo stops: at the smallest at minimum format (square), and at the biggest at the size given in the previous link. But at all other formats in between too.
• (For example: we want a 21×29.7 cm photo (state short side first), this format just falls outside the 20×20 to 20×30 range; namely, the short side is 20.3 cm, so we need to opt for 30×30 to 30×45. Thereby, the minimal format is 30.5×30.5 cm. Given our photo just falls outside that, the canvas must become 30.5×30.5 cm.
• Imagine the photo had measured 21×40 cm, then we could make the canvas 30.5×40 cm, and would be trimmed accordingly.
• Imagine the photo had measured 21×50 cm, this wouldn’t then have fitted this format, and the photo would have to be placed in a larger one. In this instance, 40×40 to 40×60. The canvas would then acquire the following size: 40.6×50 cm, and would trimmed accordingly.

Edit canvas size

So, you determined the canvas size based on the minimum and maximum formats.

• Go to Image -> Canvas size (shortcut key: Alt+Ctrl+C) and enter the canvas size. Ensure “relative” isn’t ticked , and the canvas enlargement is best set to white. Unless you would prefer a different colour as extra space around your photos.