In this review I put Van Dieman’s Harvest Series Blackberry Jam through my usual “so you know before you buy” routine. I start with my general thoughts on the color (it’s a purple in that jammy, fruit-leaning direction) and I show it across a bunch of different papers so you can see how it behaves outside of a perfect setup. You’ll see writing samples on Maruman Mnemosyne, Clairfontaine, Portage Reporter, National Steno, Rhodia, Mead Composition, and even plain 20lb Hammermill copy paper so you get a realistic spread of performance. I also do two chromatographies—one the normal way and one after the ink has been allowed to dry for 10 minutes—because I want to see what’s really in the mix and how the components hang on once it sets. After that, I run my resistance tests on Rhodia: I let the writing dry for three days, then I hit it with highlighting, water, pen flush, and a 1/3 bleach solution. I wrap up with my nib/pen/paper recommendations and I give you a color-complement ink pick (with a card at the start of that section), plus I point you to Kaweco Pearl Black as a complement I really like alongside this kind of purple.