A4 is a standard paper size that is used for many different purposes. You can purchase A4 paper from any office supply store. If you need to print something in A4 size, you can use Photoshop to change the paper size of your document.
To make an A4 size in Photoshop, open your Photoshop and click on the “Create new” button.
From there, go to the “Print” tab and select the “A4” size option. You can set up other preset details on the right menu. Once done, click on the “Create” button.
Now you have an A4 size document for your design!
Once done designing, you can proceed to print it out or save it as a PDF file with an A4 size.