Cast concrete 3D wall tiles

Shakl, a field of broken facets

Shakl is form, and it is the least regular of the six. Each face is a cluster of triangular facets meeting at apexes that sit off centre, so no two neighbours catch the light at the same angle and the field reads as a broken crystalline face rather than as a grid. Laid in one dark grey it is the pattern that most rewards a tight downlight, which picks out one facet in three and lets the rest fall away.

Mathlath, triangles in shallow pyramid

Mathlath is the triangle. Each face is divided into shallow pyramids that share their edges with the neighbouring tile, so the joint disappears and what remains is one continuous triangulated relief. It is the pattern for a large wall that has to stay calm, because the repeat is regular enough that the eye reads the whole surface instead of the individual unit.

At Optium Technologies in Karachi it runs the full height of a stair, banded from ochre through navy to crimson. The colour boundary steps along the tile edges rather than cutting across a face, which is the detail that keeps a banded wall from looking like a wall someone painted.

Khewra, hexagons set as a scattered field

Khewra is a hexagon with a low rise to the centre of each face. The shallow relief is what lets it be used sparsely: in the wall photographed here the hexagons thin out toward the edges of the panel instead of stopping on a straight line, so the field ends without a border and without a cut. Three or four greys mixed through the placement break the honeycomb before it starts to read as a motif.

Set a scattered field out on the wall before any adhesive is mixed. A hexagon has three axes and the eye finds a straight run of one tone immediately, so the placement is a drawing rather than a decision for the installer on the day.

Lehr, a wave held in a cone

Lehr is the wave, and it is the one pattern in the six with no straight line in its face. Each unit is scooped into a cone, and because the scoops line up across the joints the wall carries long ripples that a raking light turns into alternating bands of bright and shadow. Photographed here in cream against terracotta, it is the pattern that changes most between morning and afternoon.

It is also the tile on the Bahria Town Tower wall in Karachi, where the units run from white through grey to black across the field. A graded field of that kind is set out on the drawing and then boxed in order, because it cannot be corrected once the adhesive has gone off.

Arrow, a folded chevron

Arrow is the quietest of the six. The face is folded on the diagonal and again to a point, so each tile throws one triangular shadow and the field reads as a soft directional weave rather than as relief. It is what to reach for when a wall has to hold a large area without competing with whatever stands in front of it. In the courtyard photographed here it is laid in white behind a plumeria, where the sun does the work a wall washer does indoors.

Koella, coal at close range

Koella is coal, and the tile is cast to look like it: chunky angular blocks, no two faces at the same angle, standing at visibly different depths off the wall. It is the deepest relief in the range and the most demanding, because the shadows are the whole subject and a flat light kills them. Use it where a viewer passes close, on a lift lobby return, a reception back wall, the flank of a counter. Seen from across a large room it reads as noise.

Substrate, fixing, corners and returns

The tiles are heavy, so the wall behind them has to be sound, flat and cured: plastered blockwork or concrete, with any hollow render cut out before anything is fixed. They are set with a cement based tile adhesive, notched and combed so the whole back is in contact, because a relief tile bridging a void telegraphs the void as a shadow that does not line up with its neighbours. Fix from a datum struck on the wall rather than off the floor or the ceiling, since neither is as true as the pattern will be.

Decide which axis of the repeat runs true and let the cut fall on the other one. Then put the cut where nobody looks: into an internal corner, behind a return, or under a shadow gap at the skirting. A cut through a facet on the most looked at line in the room is the one thing on this page that cannot be talked away afterwards.

External corners are the decision the drawing has to make. Either stop the field short and turn the corner in a flat material with a shadow gap between them, or mitre both edges and accept that the relief will not resolve across the arris, because the facets arrive at the corner at different depths. Both are honest, and both beat a special cut on site.

Substrate

Plastered blockwork or concrete

Fixing

Cement based adhesive, fully combed

Set out from

A datum on the wall

Inside, outside, and the seventh pattern

The unit is concrete, so the same tile goes indoors and out. Outside it takes a movement joint wherever the substrate has one, and it will gather a patina in Karachi air, which the deeper patterns carry better than the shallow ones because their shadows are already doing that work. Inside, the only real constraint is the light.

Kirthar is a seventh pattern in the book rather than one of the six in production, which means asking for it before it goes on a drawing. Each square rises to a low central pyramid split into four facets, so the field reads as a grid of soft stars. On the poolside wall photographed here it is laid in cream with single deep red units scattered through it, which is the least invasive way to put colour on a wall of this kind: a handful of units, placed on the drawing.

Interior

Any pattern, grazing light

Exterior

Movement joints, expect a patina

Kirthar

In the book, not in production