Startup Idea: Customizable Book Creation and Printing Software

Startup idea to develop a software which allows users to create and print handmade books of any size, featuring customizable options such as themes, stickers, and page line rulings. The software should facilitate the setup of double-sided, book fold printing with appropriate page numbers and allow optimal page adjustments.

Junk journals and other handmade books are extremely popular. Many are made by upcycling old books. I want to make my own books of any size. I've done one using Word. I used the book gold feature so the double sided pages fall in the correct order. I set up the pages in landscape and when the pages are folded they are 5.5 X 8.5. I created several signatures, and seeds them together and then added a fabric cover. It turned out so well.

Now I'd like to make one that is 4.25 X 5.5. I just can't figure out how to set it up in Word and it's driving me crazy.

I'd like a template with the option to choose regulat or college ruled lines. I'd want to know how to print them in grey, not black.

Templates in themes with included STICKER like images would be great and I think people would pay more as this would preclude buying stickers. An image library to create your own theme would be great.

Software templates that would allow any size booklet, printed double sided, in book fold complete with page numbers could be so popular. Look up junk journals on Pinterest to see. You could probably come up with more features. Especially if everyone had a 3d printer!. I searched for how to create this size in Word. Got nowhere.I thought I could set it up to fold correctly and just trim the excess but I haven't been able to.

This is not solved!