PROPERTY / Living Histories: Out on the tiles: Master Craftsman: H&R Johnson, tile makers

IN THE heart of the Potteries, tile manufacturers H & R Johnson have revived the art of making unglazed, 'encaustic' tiles. 'Encaustic means burnt in,' says the firm's Ian Tinling. 'The pattern is not on the surface but inlaid about an eighth of an inch in the actual body of the tile. They are works of art.'

The height of fashion in the 19th century, and chosen by Queen Victoria to grace her Isle of Wight retreat, Osborne House, they were laid in the hallways and conservatories of better-off Victorian households. The medieval origins of encaustics - made by skilled potter monks for the floors of cathedrals and churches - appealed to a society enthralled by the Gothic.

Encaustic tiles today are made individually. A thick slice of malleable clay is laid over a square mould, with the design in relief at the bottom. The clay is forced tight inside with a mallet. When the slab is tipped out the design is cleanly indented. Fine coloured clays are hand-poured into the different recesses, building up the pattern, and standing slightly proud to allow for shrinkage. The tile looks lumpy, but during drying its surface is machine-milled flat. Firing in the kiln fuses all the clays together and the tile is cut to a standard six-inch square. The whole process may take seven days.

'Our finished tile is half an inch thick,' says Tinling. 'Victorian ones were over an inch, not for strength but to stop them bowing in the kiln.' They were mass-produced then. Coarse clay, sandwiched between good clay to cut costs, was rollered flat in a continuous thick strip. Patterns were impressed and the tiles chopped out mechanically, although the coloured clays were hand-applied. Factories churned out hundreds a day. H & R Johnson produce a perfect few. But their laboratory-like premises are far removed from those of the 19th century, when sickness from breathing in clay dust, and 'potter's rot' - lead poisoning from glazes - were commonplace. Maw & Co, one of the great Victorian tile-makers, even brewed a special beer containing sulphuric acid for its workforce to try to counteract the lethal effect of lead.

Tiles were fired in tall, bottle-shaped kilns, each fuelled by tons of coal and spewing out black smoke day and night. Kiln temperatures were judged by the eye of the fireman. 'Tiles at the cooler edges of the kiln might be a different shade from those where it was hotter,' says Tinling. 'When they came to be laid they often didn't fit and had to be sanded by hand.' Now, encaustic floor designs are computer-generated; the Victorian drawing office relied on tables listing numbers of tiles per square yard and probably doll's-house-sized printed tiles which could be cut up and pasted down on a plan.

By the mid-19th century there was hardly a home without tiled decoration. Glossy tiles decorated entrances from the dado down. Hearths and furniture sported tiling. Complex patterns of geometric tiles were laid in hallways and on front paths. From about the 1870s, tiled insets in fireplaces were the rage. Many were cheaply transfer-printed, the more fancy ones 'tube-lined'.

H & R Johnson employs Victorian methods to hand-make tube-line tiles today. Using a little sack of liquid clay squeezed in the palm of the hand, the artist pipes the design through a nozzle on to a plain tile - like decorating a cake - guided by a pencil sketch. (In the 19th century, a pinpricked design was made on paper and powdered charcoal tapped through the perforations.) Tube-lining particularly suits the curvaceousness of Art Nouveau designs. 'It needs a steady hand,' says Tinling - 'so no drinking the night before.'

H & R Johnson, Highgate Tile Works, Tunstall, Stoke-on-Trent ST6 4JX (tel 0782 575575)

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