UK manufacturing

Best of British: Ink in the veins

The company’s systems are also bought by printing and packaging converters

For more than 60 years, RK Print Coat instruments has been faithfully serving the global inks and coating sectors with indispensable test kits.

But since most of it stays in backroom development labs, we don’t often hear about it. Nevertheless this is a real British export success story, selling to “every well-known ink manufacturer worldwide”. And doubtless a few we’ve never heard of too.

The company’s turnover is between £4m and £5m per year, of which about 85% is exported. About 15% of sales are made in the UK directly by RK Print Coat Instruments, and it also sells about 20% directly abroad. The other 65% goes through distributors and agents worldwide. “We are very fortunate to enjoy excellent repeat business – my guess would be around 80%,” says chairman Tom Kerchiss.

Family roots

Kerchiss has worked there all of his career and can certainly claim to have ink in his veins. The company was set up by his father Roman in 1962. Roman was born in Moscow in 1913, where his father Albert Otto Kircheiss imported ink from Berlin for the Russian printing industry. Four years later the family fled the Russian Revolution and travelled to Berlin, although Tom’s grandfather died along the way. When he grew up, Roman worked in a Berlin ink laboratory until he left behind the Nazi regime in 1937 and travelled to the UK where he Anglicised his surname to Kerchiss. He then worked in the UK coatings sector until he set up his own company, which still bears his initials.

Tom Kerchiss joined the company in 1970 then studied for an OND in engineering followed by a BSc in printing technology at Watford, which at the time had one of the two biggest printing colleges in the UK. Now in his early 70s, he says he is taking a more backseat role, with day-to-day operations handled by managing director Andy James.

At first RK Print Coat Instruments was located in Great Chishill, Cambridgshire, about a mile to the east of the county border with Hertfordshire. In 1990 it upped sticks and relocated a few miles to the north west in the fields outside Litlington, to a facility designed and built by the company, and then extended in 2012. It now covers about 1,200sqm, of which 370sqm is “admin, welfare, etc”.

Today there are 30 employees, of whom 20 are in manufacturing and ten in admin.

The company has long been a keen member of the manufacturers’ association Picon, through Kerchiss. “We get assistance, support for exhibitions, etc, although UK government support has disappeared!” he says. “There are also technical seminars, export advice, etc.”

What does it make?

The company describes itself as a “specialist in the design and manufacture of equipment used to produce repeatable samples of most surface coatings.”

It makes preparation equipment and print testing equipment mainly used in three areas: research and development, quality control and small-scale production of specialist products.

Samples produced can be used for customer presentation, computer colour matching data, printability testing and to test for gloss, strength, weathering and durability. All these are vital to the increasingly industrialised printing industry that works “to the numbers”.

Kerchiss says: “We design, manufacture and assemble equipment only of our own design, with the exception of some web requirements for our VCML unit – for example, edge guide, corona treater, UV systems, etc.”

Users of RK equipment include printing ink and paint manufacturers, pigment, resin and dyestuff suppliers and manufacturers of textiles, adhesives, papers, films, foils and medical and pharmaceutical products.

Most of the ink test/proof systems are intended for flexo or gravure low-viscosity inks and coatings, though there are some for paste inks as used by litho and letterpress printing. Applications also include paints and adhesives, and high-tech coatings such as printable electronics.

“Substrates for flexible packaging include paper, films and foils,” says Kerchiss. “In the last five years, barrier coatings for paper have grown enormously as the pressure to reduce nonrecyclable films has increased.”

The kit is also bought by printing and packaging converters; for example, there are FlexiProof units to colour match prediction samples in 50 worldwide plants of a well-known but publicity shy maker of containers.

Current range

The range starts with the K-hand coater, which dates back to 1970 or so. It supplies a set of steel rods and wires called K-bars, in a set of 14, numbered and colour-coded to give accurately metered wet film thicknesses from 4 to 500microns. They are used to draw down evenly distributed stripes of ink onto paper and other media held by a clip over a board with a special impression bed. There are two sizes: 110x180mm and 220x340mm.

If more precision than hand application is needed, there’s a motorised ink applicator called the K101 Control Coater. This can be set for repeatable speed and pressure and there’s a choice of applicators. Again there are two sizes, for 170x250mm or 325x250mm. There’s a custom version for paints, too.

The K303S is a larger machine with cylinder applicators for flexo and gravure inks as well as the simpler K bars. It was redesigned in 2022 and now has a fully integrated servo drive and touchscreen control. It can apply multiple coatings in the same pass for comparison. Maximum coating area is 350x440mm with K bars and the speed can be set from 1m/min to 40m/min.

The K Lox proofer is a simple flexo applicator, available for hand holding or as a motorised unit for up to 15m/min speeds. It has an engraved roller and a rubber transfer roller, but no doctor blade. There are six engraved rollers with different screen and cell sizes.

K Printing Proofer can proof electronically engraved flat printing plates with gravure, gravure-offset or flexo inks onto most flexible substrates, with variable speeds of up to 40m/min. There are heads for direct gravure, or flexo and offset gravure, with paper held on a rubber impression roller. Wet and dry laminated samples can be produced with K-Lam laminating accessories. Standard plate sizes are 150x95mm for flexo and 160x95mm for gravure.

Esiproof is another hand applicator for flexo inks. A doctor blade allows proofing of all flexo inks, including high viscosity UV-cured types. Proofs up to a metre long and 70mm wide can be made.

Flexiproof 100/UV is a high-speed “operator-friendly” machine that’s a scaled down press unit with swing-in doctor blade and a photopolymer plate, for proofing with water-based, solvent or UV flexographic inks (a UV curing unit can be fitted). It can be used to determine properties such as wear and scratch resistance, flexibility, durability, gloss, etc. It can print on all typical commercial substrates: paper, film or foil. Speed is up to 99m/min on samples up to 240x75mm. There’s a choice of four ceramic engraved rollers, with others to order.

The GP100 is a high-speed gravure proofer for inks of press viscosity, at up to100m/min on any flexible substrate. It can use the same plates as the K Printing Proofer.

The Paste Ink Proofer (PIP) is used for letterpress and offset inks and varnishes. It has an engraved anilox roller for metering ink, avoiding the need to weigh or measure ink samples. There’s a choice of rollers for light, medium and dark coverage, plus stripes of all three. Proofs might be used for computer colour matching data, for customer samples, or to test for colour, gloss, opacity, penetration, drying, set-off, rub and abrasion resistance. It takes substrates up to 124x300mm with a print size up to 75x245mm and runs at 5m-40m/min.

The largest machines in the range are the VCM (Versatile Coating Machine) and VCML-Lab/Pilot. The VCML is designed to print, coat and laminate all types of flexible webs up to 300mm wide, such as papers, films, and metallic foils, with roll-to-roll transport. It’s intended for product development, quality control and low-volume production of specialised products. It can be configured with processes including gravure (direct, reverse, offset or differential offset), flexo or rotary screen, with a choice of drying/curing.

There’s a touchscreen control system, a servo drive with a speed range of 1m-50m/min, and integrated electrical and pneumatic controls. The whole unit is contained within a sturdy aluminium frame.

“VCM and VCML can also be used for short production runs of high added-value items that are only needed in small quantities,” says Kerchiss. Examples are size coatings for holograms, or printable electronics, solar transdermal patch coatings and flexible packaging.

Although inkjet fluids have their own requirements for test equipment, Kerchiss says there are no plans to enter that sector. “We do fit other suppliers’ inkjet heads to our VCML units for testing purposes – but would never wish to develop our own units.”

Future plans

RK Print Coat Instruments exhibits at shows and will be at Drupa this May, where it will be introducing a new unique version of the K Proofer, the KPP reverse gravure coater. “This is the go-to coating method for many barrier coatings,” explains Kerchiss.

It will also show the VCML Pilot Coater, GP100 Gravure proofer, FlexiProof unit with LED UV curing, and various hand units.


The venerable Gravure proofer was launched pre-1970, “and is still going strong!” says Kerchiss. There’s also the FlexiProof introduced at Drupa 2000, while the relative newcomer VCML Lab/Pilot coater has seen excellent sales in the last 10 years, according to Kerchiss.