I specifically purchased this 5.5" square journal for working on Zentangle® inspired art. See it's not a true Zentangle® unless it is on a 3.5" square tile. But I'm not one for coloring inside the lines so I tend to do my Zentangle® inspired art work in just about any sized journal.
This journal has wonderful paper for what I intend to do with it. It is heavyweight and 100% acid free.
The little pocket in the back of this journal is interesting. It reminds me of a CD or DVD sleeve.
So I tested it out with the items that I don't intend to use on a regular basis
Everything worked well, except the Copics and the Bic Markers. Some of the fountain pens feathered a little but that's ok.
The label indicates that the paper will accept a light watercolor wash without buckling, I guess my wash wasn't light enough, because there was quite a bit of buckling here.
The journal performs perfectly for what I want, Zentangling®. I use Copic Multiliner SP .25mm, Sakura Pigma Micron .25 and Faber Castell Pitt artist pen - brush.