Journal Paper Compared: GSM, Coating and Bleed-Through
September 20, 2026

Journal Paper Compared: GSM, Coating and Bleed-Through

The disappointment is almost always the same. You buy a notebook because the cover is lovely and the paper feels thick, then a fountain pen lays down a line that feathers like kitchen towel, or a gel pen leaves a shadow of itself on the next page. Paper is the part of a journal you cannot judge from a photograph, and the numbers on the back — 90gsm, 120gsm, "coated" — tell you less than you would hope. Here is what those terms actually mean, and how to match a notebook to the way you write.

What GSM does and does not tell you

GSM stands for grams per square metre, and it measures weight, not quality. A sheet of 100gsm paper weighs 100 grams per square metre. That is the whole of the promise. Weight does tend to rise with thickness, and thicker paper is usually more opaque, which is why heavier notebooks feel substantial and let less of the reverse side show through. But weight says nothing about how the surface behaves.

Some Japanese journal papers sit in the 50–70gsm range and handle a fountain pen far better than a 120gsm pad from a stationery chain, because the fibre blend and the sizing do the real work. If you write with a wet broad nib, a heavy but absorbent paper will still bleed. If you write with a fine gel pen, a light but well-sized paper will serve you for years. Treat GSM as a rough guide to heft and opacity, and nothing more.

  • 70–80gsm: pocket notebooks and thin lined pads. Fine for pencil and ballpoint; risky with fountain pens.
  • 90–100gsm: the common middle ground. Comfortable with most fine and medium nibs if the sizing is decent.
  • 100–120gsm: heavier and more opaque, popular with fountain pen users who dislike show-through. Not automatically bleed-proof.
  • 140–160gsm: marker-friendly and pleasant under a broad nib, though it can feel stiff and slightly glossy.
  • 200gsm and above: sketch and mixed-media territory, where light watercolour becomes possible.

Coating, sizing and the surface of the page

Coating is a layer applied to the surface of the sheet, usually a mineral such as clay or calcium carbonate, to give a smoother, less absorbent finish. In journals, the more important cousin is sizing: a treatment added to the pulp or painted onto the surface to slow the rate at which ink soaks in. Without sizing, paper behaves like blotting paper. With too much, ink sits on top and takes an age to dry.

The trade-off: definition against dry time

A well-sized or coated sheet holds ink near the surface. Lines stay crisp, edges stay sharp, and you get the shading and sheen that fountain pen users chase — that faint halo of a second colour, that soft metallic glint on a saturated ink. The cost is drying time. A wet broad nib on coated paper can take thirty seconds or more to become safe to touch, which matters a great deal if you are left-handed or writing on a train.

Absorbent, uncoated paper dries almost instantly and feels pleasant under a pencil. It also spreads ink along the fibres, so fine lines thicken, letterforms close up and bright inks look flatter. There is no perfect answer here, only the answer that suits your hand.

Bleed-through, show-through and feathering are three different problems

These get used interchangeably, and the confusion leads people to reject perfectly good notebooks.

  • Feathering is sideways spread. The line's edges go fuzzy, like a signature written on damp newspaper.
  • Show-through (also called ghosting) is when you can see the shape of writing from the reverse, but no ink has crossed the sheet. Almost every journal does this to some degree. It is usually harmless.
  • Bleed-through is when ink genuinely penetrates. You can see it clearly, it is the same colour as the writing, and it makes the back of the page awkward to use.

If a notebook shows a faint grey ghost of yesterday's entry, that is normal and you can write over it. If yesterday's entry is legible in reverse from the other side, the paper has failed you.

Matching paper to your pen and ink

The pen matters as much as the paper, and the ink matters more than most people expect. Wet nibs, flex nibs and broad stubs push far more liquid onto the page than a fine Japanese nib. Pigment inks sit on the surface and dry slowly; dye-based inks sink in faster and tend to bleed a little more readily.

  • Pencil and ballpoint: almost any paper works. Pencil actually prefers a little tooth.
  • Gel and rollerball: liquid inks bleed more than gel paste, so look for 90gsm or above with visible sizing.
  • Fine and medium fountain pen nibs: 80–100gsm, sized rather than absorbent.
  • Broad, stub, flex or very wet writers: 100gsm and up, or a paper known to be fountain-pen friendly.
  • Alcohol markers: will bleed through nearly everything short of dedicated marker paper or a heavily coated 160gsm stock.
  • Watercolour washes: you need 200gsm or above, ideally cotton, or the page will buckle and cockle.

How to test a notebook before you commit

  1. Turn to the last page, not the first. If the test goes badly you have lost nothing.
  2. Write with your three most demanding tools, not your kindest one.
  3. Use the ink you actually write with. A borrowed sample proves very little.
  4. Wait a full minute, then drag a fingertip across the line. That tells you the true dry time.
  5. Flip the sheet and look at it under a lamp, not in dim light, where everything looks fine.
  6. Note the paper's name on the inside cover. Two years from now you will want to know what worked.

Paper is not the whole notebook

It is most of it, but not all. A lay-flat binding matters if you write near the gutter, and a stitched spine will outlast a glued one that cracks in the middle of a busy month. Check the ruling too: 6mm lines suit small handwriting, 8mm suits most adults, and dotted or grid pages give you structure without shouting. Also check how many pages you are actually buying, since two notebooks of the same thickness can differ by fifty sheets.

Choosing with a bit of confidence

Start with the weight range that matches your wettest pen, then look for wording like "sized", "fountain-pen friendly" or a named paper stock rather than chasing the heaviest number on the shelf. If a notebook survives a five-line test on its last page with your broadest nib and your runniest ink, it will serve you for the whole book. Buy one, test it properly, and keep a short note of what you liked. After a few journals you will know your own requirements better than any specification on the back cover ever could.

Photo: TheDigitalArtist / Pixabay

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