The first step: the most common spine or photo album, with the cover above, the spine in the middle and the back cover below. If you create a dimension in PS, you must first change the unit to millimeters or centimeters.
Step 2: If the book needs 17cm*2 1cm, that is, the size of a page, then when creating, you need to design the size of the whole text, the front cover and back cover are both 17cm, and then calculate the middle spine according to the thickness of the book, for example, the middle thickness is 2cm, so when creating, you need the sum of two covers plus the middle book.
Step 3: This creates a cover size, then you need to pull out the reference lines to determine their respective positions, open a new reference line in the view, and then the first reference line is the page size of the book 17cm.
Step 4: Create the second reference line and add the spine thickness of 2cm, that is, at 19cm.
Step 5: In this way, the middle three parts are separated, and each text and picture needs to be completed in its own area.
Step 6: After the design draft comes out, it needs to be printed, and the edge part will be cut off when printing, so it is also necessary to add the size of bleeding. Generally, the bleeding is 2mm or 3mm. If 3 mm is given, there is one side for the top, bottom, left and right. Bleeding can be added when the canvas is created, or bleeding lines can be added after the design.