Book binding experiments - exposed stitching

I went to ask how to bind a book with exposed stitching on Tuesday and Sarah said to come back during a drop in session so i went today. She taught me the technique and we made a rough book just to get the idea of how to do it. The fat book with black stitching below is the one i made in the session, and then when i went home i tried again with materials i would like to use for my final book idea. The book i created was using tracing paper pages and is the thinner one with light gray stitching (shown below)