Pen & Paper
Specimen The Paper Archive Search ⌘K

Weight
Tooth
Sheen
Bleed
Tone
Dry time
№ 01 · Attributes

The sheet, by every measure.

All readings under standard lab conditions — 21 °C, 50 % RH, Iroshizuku Tsuki-yo on a Medium 14k.
Identity & Provenance i.

The mill, the lineage, and the line this sheet belongs to.

BrandTomoegawa
Mill (current)Sanzen Paper Co.
ModelTomoe River S
VariantLoose A5 · 100 sheets
SucceedsTomoe River (original, 2019†)
CountryJapan
Mill locationShizuoka Prefecture
Year introduced2019 (S revision)
Archive number№ 001 / 140
StatusIn production · widely stocked
Substance & Composition ii.

What the sheet is made of, how thick it is, and how much light passes through.

Weight52 gsm very thin
4080100120160
Caliper53 µm
Bulk1.02 cm³ / g
Opacity3 / 10 — translucent
SheerTranslucentSolidOpaque
Pulp sourceWood pulp · ECF-bleached
Cotton content0 %
Recycled content0 %
Acid-freeYes
ArchivalYes — ISO 9706
pH7.2 — slightly alkaline
LigninTrace
Ash content12 % · calcium carbonate
Brightness (CIE)82
Brightness (ISO)78
L* / a* / b*93.4 / 1.1 / 8.6
Optical brighteners (OBA)None
Tone familyCream · warm
Surface & Finish iii.

What the nib feels under the hand — and what keeps the ink on top.

ToothGlass · 1 / 10
GlassSmoothSoft toothToothy
FinishWove · calendered
Bekk smoothness2 400 sec · very smooth
Sheffield smoothness25 · polished
Gurley porosity1 800 sec / 100 ml · closed
Cobb (60 s)14 g / m² · low absorbency
Gloss (75°)8 % · matte-satin
Surface directionFelt side · uniform
SizingExtreme surface
NoneLightHeavyExtreme
CoatingUncoated · sized
HygroscopyHigh — store sealed
Moisture content4.8 % · at 50 % RH
Grain directionLong-grain · vertical
Deckle edgeNone — machine-cut
Behaviour with Ink iv.

Feathering, bleed, ghosting, sheen, shading — measured against the catalogue's distribution.

Feathering1 / 5 — nil
NilTraceVisibleHeavy
Bleed-through1 / 5 — none
NonePinpointSpotsSoaks
Show-through (ghost)4 / 5 — heavy
NoneSlightModerateHeavy
Sheen visibility5 / 5 — pronounced
MatteVisiblePronouncedMirror
Shading visibility5 / 5 — vivid
FlatModestVisibleVivid
Shimmer visibility5 / 5
LostVisiblePronounced
Dry Time · by Nib v.

Seconds to a smudge-free pass. Standard ink: Iroshizuku Tsuki-yo, room conditions.

Extra-fine (EF)22 s
5 s30 s60 s
Fine (F)28 s
5 s30 s60 s
Medium (M)38 s
5 s30 s60 s
Broad (B)48 s
5 s30 s60 s
Left-hand viableWith patience · or EF only
Double-sidedYes — ghosting accepted
Watermark & Texture vi.

What the sheet shows against the light, and what the hand reads of its surface.

WatermarkNone
Chain linesNot visible
Laid linesNot visible — wove sheet
FormationUniform · cloud-free against the lamp
Felt sideUniform · no preferred side
Wire sideCalendered to match
Texture ratingGlass · 1 / 10
EmbossingNone
Edge treatmentSquare cut · no deckle
Mill & Heritage vii.

The mill, the machine, the certifications — and the story of the predecessor sheet.

Mill founded1914
Original makerTomoegawa Co. Ltd
Current makerSanzen Paper Co. (2019–)
Machine typeFourdrinier — narrow web
Machine speed~ 380 m / min
Predecessor sheetTomoe River (original, 2019†)
FSC certificationYes — Mix · FSC-C012345
PEFCNo
ISO 9706 archivalCertified
Carbon footprint~ 0.86 kg CO₂e / kg
PulpingECF · elemental-chlorine-free
Format, Binding & Sizes viii.

How the sheet is sold, bound, ruled — and in what sizes.

Format kindLoose-leaf · pad
Sheet count100
BindingGummed top · padded
Lays flatYes — fully
CoverCard backer · no front
PerforationNone
Sizes available
A5 A4 A6 B5 Letter Roll · 36 cm
Rulings available
Blank Ruled · 6 mm Dot · 5 mm Grid · 5 mm
Dimensions (A5)
148 × 210 mm
Best for nib size
M B BB Stub Flex
Best for ink flow
Wet Very wet Medium
Avoid for
Pencil work Hard pressure Heavy erasing

Editor's note · A. Reber

A paper that exists because some inks needed somewhere to go. Reserve for the ones whose second colour — the sheen — is the whole point.

Care notes

  • Store sealed→ humidity
  • Keep flat→ curl
  • Don't fold→ creases set
  • Allow 60 s→ wet inks

Pricing

€ 8 · A5 pad of 100
€ 22 · A4 pad of 100

Tier I · ~ €0.08 per sheet

№ 02 · On the Page

The same paper, three different pens.

All samples in Iroshizuku Tsuki-yo, indoor 2700K. Affinity scored against this sheet.
№ 03 · Recommended Marriages

Pairings featuring Tomoe River.

From the catalog. Sorted by affinity.