Turned to order, one at a time

One rod of hard rubber, turned until it fits the hand.

Ebonite is a one-person shop. Cap, barrel and section come off the same 15 mm rod of vulcanised hard rubber, so the pattern runs through all three. Four hours and ten minutes at the lathe.

See the line it makes Read the measurements

Material: Vulcanised hard rubber
Length: 138.0 mm capped
Weight: 19 g filled
Fill: Eyedropper, 3.1 ml

What happens between the rod and the box

Nothing here is a secret. It is one tool post, four hours, and a great deal of sanding. The shop writes the numbers down as it goes, and those are the numbers printed below.

StockCut from a 15 mm rod. Cap, barrel and section come off the same stick, so the pattern runs through all three.1 rod

TurningRoughed, then finished between centres in one setup so the taper never steps.4 h 10 min

ThreadsSingle start, cut on the same chucking as the bore. The cap comes off in a turn and a quarter.1.0 mm pitch

SandingEleven grits, wet, then burnished dry. No lacquer and no buffing wheel.400 → 12000

WritingEvery nib is written in before it ships. Two pages, the same paper each time.2 pages

The line it makes

Four grinds leave the shop. Pick one and the sample below is redrawn at the width that nib actually lays down.

Written on 80 g/m² paper, one pass, no retouching.

Line width: 0.30 mm
Tipping: 0.42 mm
Time on the stone: 26 min

Hard rubber, and what it does

Natural rubber cured with sulphur. It was the first pen material, it went out of fashion when celluloid arrived, and it is still the warmest thing to hold.

CompositionNatural rubber vulcanised with sulphur, about a third of the finished weight.32 % sulphur

DensityLighter than acrylic, which is how a full-sized pen still lands at 19 g.1.18 g/cm³

WarmthMoves heat slowly, so the grip sits at hand temperature within seconds.0.16 W/m·K

PatinaSunlight turns black rubber brown. Two minutes with the burnisher takes it back.Reversible

SmellThe sulphur is real. It fades over the first weeks and returns for a minute after a wash.3 weeks

Measured, not estimated

Taken off the last pen out of the shop with a 0.01 mm caliper. Every pen is measured before it is boxed, and the sheet goes in with it.

Length cappedFinial to finial, cap seated.138.0 mm

Length openNib to tail with the cap off.126.4 mm

BarrelAt its widest, just behind the cap lip.13.6 mm

GripAt the narrowest point of the section.10.4 mm

WeightFilled, cap on.19 g

CapOn its own.7 g

CapacityEyedropper filled, up to the last thread.3.1 ml

ThreadsSingle start, cap to barrel.1.0 mm pitch

Lathe timeRoughing cut to final pass.4 h 10 min

FinishWet sanded through eleven grits, burnished dry.400 → 12000

Nothing is turned until somebody asks for it.

Batches of six. Six to eight weeks from the order to the post office, and the shop writes on the day the rod is cut. If the pen is not right in the hand, it comes back and gets turned again.

Ask for a pen Write to the shop

Ebonite Hard rubber pens, turned to order