Home > Info > FAQs > Book Design & File Preparation > Common Questions
Let's be honest here. Book Design? File Preparation? It's all a big pain, isn't it. If you're reading this FAQ and it's in one ear, out the other, then it might be worth checking out our Free File Assessment where we can check over your files, tell you what's wrong and help you fix it. Easy as pie.
What file format should I supply my files in?
It has to be said, we're not a fan of Word Documents or Adobe InDesign files. I mean, we work with them, but we're not a fan of them. If you can send us a PDF then we'd be super grateful. If you're still stuck on how to supply your files then click here to find out what we recommend (or give us a call if you're really stuck, we won't tell anyone).
How do I calculate the size of my book spine?
This one's easy. Use our simple spine calculator and that'll work it out for you. Just don't forget to add 2mm onto the calculation if you're printing a hardback.
What is 'bleed' and when do I need to add it?
This is a bit of a longer one. The basic idea is this. If you try to cut out a picture in a magazine, even if you're suuuuuper good at cutting, there is going to be a tiny bit of space outside the picture left when you're done. Either that, or you will have to cut some of the picture off.
The same happens when we're trimming your book. We either have to cut some of your picture off the edge, or you're left with a little white border (which is really ugly). The bleed is this part of the picture that we cut off. Just make sure your page is 2.5mm bigger on every edge and we will do the rest.
Here's an example if you're better with numbers. I want a 210 x 297mm book with a picture going to the edge of the page, so the width of my document is 210mm + 2.5mm (for the left side) + 2.5mm (for the right side) = 215mm. The height of my document is 297mm + 2.5mm (for the top) + 2.5mm (for the bottom). So my final document size is 215 x 302mm. We will take this document, print it off and cut 2.5mm off each edge, leaving just the 210 x 297mm I wanted to keep.
This is tough so don't be put off if you're not quite getting it. You can either use our free file assessment and we'll let you know if you need bleed, or you can give us a call to get another explanation.
How big do my book margins need to be?
Paperbacks and hardbacks? Make your outside, top and bottom margins 15mm, with your inside edge at 18mm. Booklets and coils? You can get away with 12mm on every edge. Still aren't sure? Download one of our book templates to make it easy.