16°21′E16°22′E 48°12′N48°12′N
ChartNo. 1070
INSEL THOMASPottery & Soundings · Vienna
First edition 2026
Scale 1 : 1 (it’s small)

Sailing Directions · Chapter 2

Tide Flats

Forty serving bowls, and a winter spent teaching one blue glaze where to stop.

PositionS shore, dries at low water
OccasionSpring design market, Ottakring
Quantity40 bowls, 60 test tiles
MaterialStoneware, unglazed exterior
GlazeTile 47, a blue that runs and stops
StatusSold out. Recipe in daily use
Inset · Tide Flats markedNot to be used for navigation
2.1

Description

A run of forty serving bowls for a two-day design market. The idea was one line on each bowl, two-thirds of the way up, where blue glaze gives way to bare clay, like the mark the tide leaves on a harbour wall.

2.2

Works undertaken

Dipping a bowl gives a hard, wobbly edge, which looks like a mistake. Thomas wanted the glaze to find its own line in the kiln: run down just far enough and stop.

He spent a winter on it. Sixty test tiles, each with a slightly different amount of silica and a slightly different thickness of glaze. Tile 47 did it: a blue that slides about a centimetre in the firing and then holds, leaving a soft edge that looks like water that has just gone out. Below the line he left the clay bare and sanded it until it felt like a stone from a beach.

2.3

Changes since last survey

All forty bowls sold on the first morning of the market. Tile 47 is now the base for everything blue Thomas makes. And “where does the glaze stop?” became the first question he asks about every new piece, before shape or size.

Ø 240 mm tide line bare clay,sanded like beach stone tile 47 blue,pooling inside
Fig. 2 · Tide bowl, half-section. Dashed line marks where tile 47 comes to rest.

CAUTIONThe bare clay below the tide line is porous. Wipe, don’t soak.