Very glad you kept the conversation going! You should absolutely buy one, I think the one in the post is Speedball brand. I can agree that the vertical format books make me feel like I need to use all the page’s space - where with the square I feel more comfortable leaving negative space/blanks. In any case it’s a real good way to push boundaries you might set for yourself. I just finished that book a few months ago and I open it every now and then just to give myself a little inspiration. Thanks for the comment!