We tested five pens on the same sheet of our 160gsm paper: a fine-nib fountain pen with standard ink, a wet broad nib, a 0.5mm gel pen, a fine-liner, and a dual-tip brush marker.
Results
- Fine fountain nib — no bleed, very light ghosting
- Broad fountain nib, wet ink — no bleed, visible ghosting on the reverse
- 0.5mm gel pen — no bleed, no ghosting
- Fine-liner — no bleed
- Brush marker, heavy coverage — no bleed at normal pressure; pressing hard in one spot can mark the reverse
What this means in practice
For everyday note-taking, highlighters and gel pens, 160gsm behaves like card stock: nothing reaches the other side. For art markers with alcohol ink, no uncoated paper will hold indefinitely, and you should still use a blotter sheet.
The test you can run yourself
Open the journal to a middle page, write a heavy line, wait thirty seconds, then look at the back under a lamp. Ghosting is normal; wet spots are bleed. If you see wet spots on 160gsm, the ink, not the paper, is the variable.
All SeQeS journals use the same paper stock, so a test on one design applies to every A5 cover.