MartinEM

This. I'm with you on this one. We need a spine feature. Sure, I can calculate it and use guides but it would be a great time saver if I could adjust spine width on the go. Especially when the client gets back to you wanting to fit extra chapter in there. Most of the time I start a cover art project without final book measurements. Once I get them I always have to adjust the spine. Rulers should have that option. Like set 0 in the middle of your spread and adjust spine width from there. Once you set the spine width with rulers it should apply guides automatically.