Made once, made properly.

Printed straight onto metal.

Each photograph is printed directly onto its panel on a large-format UV printer. Ultra-fine droplets of ink are laid onto the surface and cured by ultraviolet light in an instant, so the colour sits on the metal rather than sinking into paper.

Nine ink channels, among them two light tones, a white and a clear varnish, hold the quiet greys of a plaster wall and the orange of rust without banding. The inks are rated to last more than seventy years indoors.

Before anything is made, your Quartet is test printed and checked by eye against a calibrated screen. You approve the proof, and only then is anything charged.

Four plates, floated.

Each panel is aluminium composite: two skins of aluminium, 0.3 mm each, bonded to a polyethylene core, 3 mm in all. It is light, perfectly flat, and will not warp or delaminate.

Each plate is cut to size, its edges finished by hand, and set on a small sub-frame that holds it 12 mm off the board. That gap is what throws the soft shadow you see around every image.

A tray, and no glass.

The four plates sit on archival, acid-free cotton museum board, inside a tray frame of black-finished timber from FSC-certified forests.

There is no glass. Nothing comes between you and the surface: no reflection, no green cast, just the grain of the paint and the metal beneath it.

Signed, sealed and listed.

Every Quartet carries a tamper-evident hologram on its back. Its certificate is signed by Harrop and bears the same code, and the work is entered on the List, in its owner's name or in private.

Then the code is retired. Those four photographs, that way up, are never made again.

If the work ever changes hands, its new owner is recorded on the List and a new certificate is issued in their name. Its history stays with it.

Choosing a size.

As a rule, a work should be about two-thirds the width of the furniture below it, and hang 20 to 25 cm above it.

• Quartet, 76 × 102 cm. Above a two- or three-seat sofa, a sideboard or a bed; in a hall, or on a landing.
• Grand Quartet, 105 × 140 cm. Above a long sofa or console, in a dining room, or at the end of a long view.
• On an open wall, hang the centre of the work 145 to 150 cm from the floor: eye level, as in most galleries.

Not sure? Choose In a room on any Quartet to see it to scale, or send Harrop a photograph of your wall.

Ready to hang.

Each Quartet arrives with its fixings already on the back, sized to its weight. Into brick or block, use wall plugs and screws; on plasterboard, heavy-duty cavity fixings rated well above the weight. A Grand Quartet, or a set, hangs on a split batten, so it sits level and flat to the wall.

Hang it out of direct sunlight, and away from radiators and fires.

Crated, insured, anywhere.

Your Quartet is wrapped, protected at every corner and fitted into a made-to-measure wooden crate, then sent by a specialist fine art courier, insured for its full value until it reaches you. Delivery is included, anywhere in the world. In London, Harrop can deliver and hang it himself.

1. ProofWithin a week of your request
2. MakingSix to eight weeks
3. DeliveryDays in the UK; one to two weeks overseas

Looking after it.

• Dust the plates lightly with a soft, dry microfibre cloth, in one direction.
• Never spray anything onto the work. For the frame, a barely damp, lint-free cloth.
• Handle it by the frame, never the plates, and wear cotton gloves to move it.
• If a plate is ever marked, write to works@harrop.works.