In the beginning I wanted to write a huge core rulebook for my sci-fi setting, that would have been a terrible mistake. I spent thousands of dollars on worldbuilding the art bible and very few people can afford to go thousands of dollars into art and writing and then publish a book nobody may actually want to an audience that may not exist.

What I should have done instead was come up with a minimum viable product, a book of equipment or feats or something even a rules light quickstart would have been better. Come up with an outline, a budget and just buy the art for that, then publish it and see if anyone cares. If you make a few mistakes along the way you can update the files and move on. If I had continued working on the big core book we’d still be waiting.

The Cover
Custom full page cover art is expensive, you are going to cover it up with a logo and a title anyway. Sometimes half page art or character art with a textured background makes a decent cover. Sometimes a couple of spot illustrations laid next to one another on a background will make a decent cover.

Maps
Maps need titles, scales and they need compass points. However, if you can separate the labels on your maps from the artwork then the GM can use them in VTTs or on a tablet or printed maps without having to remove things the players wouldn’t know about. On our early maps the art and labels were all one graphical image, on later maps the maps are art and the labels are text boxes in InDesign.

Print on Demand

Colors, when you buy art you can get in in JPG, PNG or TIFF, but some of these formats are RGB which is fine for the web and PDF publishing, but if you want to print something you need it o convert to CMYK and do it well. Only some of these formats can have a transparent background which you’ll want to be able to lay things over and next to your text pages.

Lightning Source’s 240% ink limit, the amount of ink that Lightning source can put on paper and not saturate the page is 240%. you can get an ICC profile for the model of printer used by Lightning Source and include that in your export process in InDesign, you can also use the ICC profile to preview how close you are to the Ink Limit in InDesign.

When you finally make the leap from digital publishing PDFs to Print on Demand, you nice symmetrical two column layout with equal borders on left and right sides that looks fine on a tablet does not look fine in print. If you don’t have enough inside margin then your text column closest to the spine gets hard to read without forcing the book apart. The more pages in the book, the worse this inside margin problem gets.

Color backgrounds, print on demand books are not always cut as precisely as offset print runs. If your color background stops exactly at the edge of the page you will get little while lines around the edge of your pages where the printer trimmed the pages and your color background stopped. Push your color backgrounds and full page artwork into the bleed area to account for issues with badly trimmed pages. You may need to ask the artist to give you some extra border area around the image to accommodate this.