In UV flatbed printing, the ink you select is not a minor detail — it is the foundational decision that determines which materials you can print on, what surface quality you will achieve, and how durable the finished product will be. Unlike roll-to-roll printing where media characteristics are relatively uniform, flatbed printing spans an extraordinary range of substrates: hard acrylic sheets and brittle ceramic tiles at one extreme, soft leather and stretchy silicone at the other. No single ink chemistry can serve both worlds equally well.

The Roland VersaOBJECT IO-300 addresses this challenge with a deliberate dual-ink strategy. Rather than offering one general-purpose UV ink and asking operators to compromise, Roland engineered two distinct ink families for the IO-300: EUV-HP (also referred to as EUV-H or EUV-HP7) for rigid industrial substrates, and EUV-A7 for flexible and soft materials. Each ink is optimised from the ground up for its substrate category, delivering surface adhesion, mechanical flexibility, and special-effects capabilities that a compromise ink could never match.

This guide walks through every dimension of the IO-300's ink system — from the fundamental chemistry differences between EUV-HP and EUV-A7, through special effects like gloss varnish and embossing, to practical considerations like white ink density, colour stability, ink consumption, and the significant advantages of Roland's 750ml pouch cartridge system over competing bottle-type designs. For background on the machine itself, see the full IO-300 introduction.

1Two Ink Families, Two Worlds

The IO-300's ink philosophy starts with a simple recognition: rigid substrates and flexible substrates have fundamentally different mechanical requirements. A UV ink that adheres excellently to acrylic will crack and flake when printed on leather — because leather flexes, stretches, and compresses with use. Conversely, an ink formulated for flexibility often sacrifices the film-forming strength and solvent resistance needed for industrial rigid applications. The IO-300 resolves this tension by making the substrate category the primary selection criterion before anything else.

2EUV-HP: The Industrial Rigid Ink

EUV-HP (specification name EUV-HP7) is Roland's high-coating performance UV ink engineered specifically for the demanding requirements of rigid industrial decoration. Where a standard UV ink might achieve adequate adhesion to a substrate with post-print curing time, EUV-HP is formulated from the outset to form a robust, chemically stable film on non-porous hard surfaces that experience mechanical stress, chemical exposure, and outdoor conditions.

High Film-Forming Chemistry

The defining characteristic of EUV-HP is its film-forming behaviour. When UV curing occurs, the ink's polymer chains cross-link at a density that produces a cohesive, mechanically strong film rather than a brittle surface deposit. This means the ink layer itself functions as a durable coating — not just a carrier for pigment — which is why Roland classifies EUV-HP as an "industrial decoration grade" ink. The film resists chipping, flaking, and delamination even when substrate edges are sharp or cut after printing.

Solvent Resistance

Industrial applications often involve cleaning agents, disinfectants, cutting fluids, or incidental chemical contact. EUV-HP's cross-linked film structure provides meaningful resistance to common solvents, making it suitable for product marking, industrial panel decoration, and applications where the printed surface may be wiped down with isopropyl alcohol or similar cleaning compounds. This is a material requirement for sectors like automotive parts decoration, industrial equipment labelling, and medical device components.

Substrate Compatibility — EUV-HP

• Acrylic (PMMA) & Polycarbonate The most common flatbed print substrates. EUV-HP achieves excellent adhesion on both cast and extruded acrylic, and on PC sheets — critical for backlit signage, display components, and industrial panels.
• PET (Polyethylene Terephthalate) Used extensively in packaging, labels, and electronic overlays. EUV-HP bonds to PET surfaces with strong layer adhesion, resisting flex-cracking at sheet edges.
• ABS & Engineering Plastics ABS, polypropylene, and similar engineering plastics used in consumer electronics, automotive interiors, and appliance panels. EUV-HP handles the low-surface-energy characteristics of these materials effectively.
• Aluminium, Steel & Metal Panels Metal substrates used in industrial nameplates, architectural cladding, and equipment panels. EUV-HP provides adhesion to both bare and pre-treated metal surfaces.
• Glass & Ceramic Tiles Non-porous, high-gloss surfaces that challenge most UV inks. EUV-HP's film-forming chemistry enables production-grade printing on glass panels, mirrors, and glazed ceramic tiles for interior decoration.
• Wood & MDF Porous substrates used in furniture decoration, signage boards, and architectural products. EUV-HP penetrates and seals the surface for vibrant colour reproduction on natural and engineered wood products.
• Paper & Coated Board For premium paper-based applications where UV curing provides a protective surface coating alongside the colour print — packaging proofing, art prints, and display board.

Colour Gamut: True Rich Color on EUV-HP

When combined with Roland's True Rich Color colour management profile, EUV-HP achieves a colour gamut that approaches that of the MO-240 running EUV5 ink — a benchmark machine known for its gamut performance in the UV flatbed category. This is a meaningful technical achievement: the IO-300 is Roland's entry into a new flatbed format segment, and delivering near-MO-240 gamut quality on rigid substrates validates EUV-HP as a serious production-quality ink system, not merely an introductory offering.

3EUV-A7: The Flexible Soft-Material Ink

EUV-A7 represents a completely different engineering philosophy. Where EUV-HP is built for hardness and chemical resistance, EUV-A7 is engineered for mechanical compliance — the ability to flex, bend, stretch, and compress without the ink film cracking, delaminating, or losing adhesion. This is non-trivial chemistry: UV-cured inks are inherently more brittle than solvent or water-based alternatives because the cross-linking process that gives them durability also reduces their elongation-at-break.

Roland's solution is a flexible resin matrix in EUV-A7's polymer system that maintains cross-link density for durability while incorporating molecular-level flexibility mechanisms that allow the cured film to deform elastically. The result is an ink that stays bonded and intact through the repeated mechanical stresses that soft materials experience in real-world use — stitching, folding, stretching, and pressure contact.

The MO-240 Connection

EUV-A7 is not a new development created exclusively for the IO-300. It is the same ink family used in the Roland VersaOBJECT MO-240 — Roland's established UV flatbed printer for soft materials. This lineage is significant: operators who are already familiar with EUV-A7 performance characteristics on the MO-240 can bring those expectations directly to the IO-300 without recalibration anxiety. The ink behaviour, colour profiles, and substrate compatibility guidance accumulated from MO-240 deployments applies to the IO-300's EUV-A7 configuration.

Substrate Compatibility — EUV-A7

• Genuine Leather & Full-Grain Hides The premier soft-material application for UV flatbed printing. EUV-A7 adheres to the natural texture of genuine leather without cracking through the flexion involved in leather goods — wallets, bags, belts, straps, and upholstery panels.
• PU Leather (Polyurethane Synthetic Leather) The dominant material in mid-range leather goods, automotive interiors, and furniture. PU surfaces have a micro-texture and flexibility profile similar to genuine leather; EUV-A7 handles both with consistent adhesion.
• Fabric & Textiles Woven and non-woven fabrics used in promotional products, garment decoration, accessories, and soft signage. EUV-A7 penetrates fabric fibres to achieve mechanical bonding alongside chemical adhesion.
• Silicone Silicone substrates — phone cases, wristbands, medical devices, kitchen accessories — are notoriously difficult to print on due to their extreme low surface energy and high elasticity. EUV-A7's flexible formulation handles silicone's stretch characteristics. To see the full range of objects the IO-300 can decorate, explore the full applications guide.
• Neoprene Used in sportswear, laptop sleeves, promotional items, and wetsuit materials. Neoprene's closed-cell foam structure requires an ink that can follow surface compression without cracking.
• Soft Rubber & Elastomers Industrial and consumer rubber products including mats, gaskets, protective pads, and grips. EUV-A7 maintains adhesion through the compression-recovery cycles these materials experience in use.

4Special Effects with EUV-HP

One of the IO-300's most commercially compelling capabilities is its suite of special effects — all available exclusively with EUV-HP ink. These effects transform flat printed graphics into tactile, three-dimensional surface experiences that command premium pricing and open application categories that simple CMYK printing cannot address. Four distinct special effects modes are available, each with specific production speeds and application characteristics.

Gloss Varnish

Gloss varnish deposits a clear, high-sheen UV-cured layer precisely over selected areas of the printed image. Unlike flood-coating an entire sheet with gloss laminate, the IO-300 can apply spot gloss digitally — placing shine exactly where the design specifies, down to fine text and intricate graphic elements. The result is a contrast between gloss-coated and uncoated areas that adds visual depth and a premium tactile quality to the output. Production speed: 1.1 m²/h in standard mode.

Matte Varnish

The inverse of gloss varnish: a UV-cured layer with a controlled low-sheen surface that reads visually as a soft, sophisticated finish. Matte varnish is increasingly in demand for packaging, product decoration, and luxury goods where a matte aesthetic signals premium quality. As with gloss, matte can be applied as spot coating — enabling the same image to carry both gloss and matte zones in a single print pass sequence. Production speed: 0.9 m²/h in standard mode.

Embossing (Gloss)

Embossing deposits multiple layers of gloss varnish in register to build physical height on the substrate surface — creating a tactile raised texture that can be felt with a fingertip. The IO-300 achieves this digitally without physical dies or stamps, meaning embossing can be applied to any area of any design without tooling costs or minimum order constraints. Production speed: 2.6 m²/h in standard mode. For detailed thickness data, see Section 4 table below.

Matte Embossing

The same build-up process as gloss embossing, but using a matte-finish clear layer that produces raised surface texture with a non-reflective appearance. Matte embossing is particularly effective for simulating tactile materials such as linen, leather grain, or technical surface textures in product decoration. Production speed: 2.0 m²/h in standard mode.

Gloss Embossing Thickness: IO-300 vs MO-240

One of the IO-300's standout technical claims is that its single gloss channel achieves greater embossing height per layer than the MO-240's dual gloss configuration. This is a meaningful advantage: the IO-300 does not need to dedicate two ink slots to gloss to outperform a dual-gloss competitor. At 10 layers, the IO-300 single GL reaches 0.97mm — versus the MO-240 dual GL at 0.80mm. That 21% additional height is perceptible to the touch and visible to the eye.

The practical implication for operators: if you are producing embossed-effect products — business cards, awards, branding panels, packaging prototypes — the IO-300 running a single gloss slot delivers more impressive tactile results than a printer that requires dual gloss slots to reach a lower height. That freed-up ink slot can be used for primer, a second white layer, or the second gloss for even greater height when needed.

5White Ink Performance

White ink is arguably the most technically demanding channel in any UV flatbed printer. It must achieve sufficient optical density to provide an opaque base layer on coloured or transparent substrates, while remaining stable in the ink system, resisting settling and clogging, and delivering consistent density across the entire print width. On the IO-300, white ink performance benchmarks against the MO-240 — Roland's established reference machine for UV flatbed quality.

Understanding White Ink OD Values

Optical Density (OD) is the standard measurement for white ink opacity. A higher OD value means more opaque, more reflective white output. For reference, a standard OD of 0.40 produces a visually clean white that reads as clearly opaque on a black substrate. Below 0.35 OD, white starts to appear translucent or washed-out in direct comparison. The IO-300 achieves a white density OD value of 0.38 in dual white, standard mode — a figure that positions it firmly in the production-quality category.

The MO-240 achieves 0.45–0.6 OD in High Quality mode with dual white — a higher ceiling that reflects its position as a dedicated specialist in the soft-material UV segment. The IO-300's 0.38 OD in standard mode is the baseline; using dual white configuration and High Quality mode settings will push output closer to the upper end of the range. For the majority of rigid-substrate applications — white base on glass, white underbase on dark acrylic, white highlight on metal — 0.38 OD delivers excellent visual results.

Simultaneous CMYK + White Printing

The IO-300 supports simultaneous printing of CMYK colour and white in a single pass, enabling white-underbase workflows at full production speed without requiring separate white and colour passes. Simultaneous CMYK-to-White or White-to-CMYK printing runs at 3.2 m²/h in standard mode. This is a significant productivity advantage for high-volume operations printing on coloured or transparent media where a white layer is structurally required for colour accuracy.

White Ink Configuration

The dual-white slot configurations available on the IO-300 (CMYKWhWhGlPr and CMYKWhWhGlGl) dedicate two of the eight ink positions to white — reflecting the practical reality that white ink consumption is typically 5–8 times higher than CMYK per unit area on underbase applications. Having two white slots ensures that high-volume white printing jobs do not deplete a single cartridge faster than the printer's replacement cycle allows, maintaining consistent white density throughout a production run.

6Colour Stability: The ΔE00 Factor

UV-cured inks undergo a brief period of colour shift immediately after printing and curing, as the cured polymer film completes its internal molecular relaxation and any residual photoinitiated chemistry settles. For production environments where printed pieces are compared against each other — or against a colour proof or brand standard — this post-cure shift can create visible ΔE discrepancies between prints made at different points in a production run. Managing this shift is a real operational concern in colour-critical work.

EUV-H Ink Stability Performance

EUV-H (EUV-HP) ink on the IO-300 achieves a ΔE00 value of 2 or less within 30 minutes after printing. ΔE00 is the most perceptually accurate colour difference formula in current use; a ΔE00 of 2 is at the threshold of what an untrained observer would notice under standard viewing conditions, and well within the tolerance accepted by most brand colour management standards. In practice, this means that after a 30-minute stabilisation window following print, EUV-H output is colour-stable and safe for production comparison and proofing workflows.

Why Colour Stability Matters for Production

• Brand Colour Matching Products printed for clients with strict brand colour standards (Pantone references, corporate identity guides) require consistent ΔE between pieces. A ΔE00 ≤ 2 stabilisation within 30 minutes allows proofing and production runs to use the same colour reference without time-dependent drift.
• Batch Production Consistency When printing multiple copies of the same job across several print passes, pieces from the first pass and pieces from the last pass must match. Rapid colour stabilisation with EUV-H ensures early and late sheets share the same colour state within the production window.
• Quality Control Sign-Off QC inspection of printed output can proceed 30 minutes after printing rather than requiring an extended hold. This reduces work-in-progress holding time and allows faster job throughput from print to finishing and dispatch.
• Colour Proofing Reliability When the IO-300 is used as a proofing device for production colour verification, the stable ΔE00 performance of EUV-H ink ensures that a proof produced today and reviewed tomorrow still accurately represents the approved colour state.

7The 750ml Cartridge Advantage

Beyond ink chemistry, the IO-300's ink delivery system represents a considered design decision that has direct implications for operator experience, ink management, and total cost of ownership. Roland selected a 750ml pouch cartridge format with IC chip identification — a system that addresses several pain points that operators familiar with competing bottle-type UV ink systems will immediately recognise.

Clean Hands Operation

The most immediately tangible difference between the IO-300's cartridge system and Mimaki's LH-100 bottle-type ink is cleanliness. (For a full head-to-head assessment, see the IO-300 vs Mimaki comparison.) Mimaki LH-100 ink bottles require the operator to pour or transfer ink manually, and the area around the ink system is chronically contaminated — UV ink on hands, on surfaces, and on the machine. UV ink is a skin sensitiser and should not be handled without protection; in practice, operators working with bottle-type systems frequently contact ink despite best intentions.

The IO-300's sealed pouch cartridges insert and remove without any ink transfer. The ink does not leak. Operators change cartridges with bare hands without risk of skin contact. This is not a minor convenience — it is a meaningful health and safety improvement, and it also reduces the time cost of managing ink changes and cleaning up after them.

No Shaking Required

Mimaki's white ink — in common with many pigment-heavy UV inks — requires shaking before use to re-suspend settled pigment. The recommended procedure for Mimaki white involves holding a Kim Wipe over the bottle opening to prevent spill while shaking — an awkward, messy operation that is easy to do incorrectly. Roland's 750ml pouch cartridges do not require shaking. The pouch format and IC chip system ensure ink is drawn from the cartridge in a controlled manner that maintains pigment suspension without operator intervention.

Shelf Life: 12 Months vs 3 Months

This is perhaps the most significant operational difference from a cost management perspective. Mimaki LH-100 ink has a shelf life of only 3 months after opening. For operations that do not run the IO-300's equivalent print volumes continuously, this creates a genuine wastage risk — opened cartridges that expire before they are consumed. Roland's 750ml cartridges carry a 12-month shelf life — four times longer. This fundamentally changes inventory management: operators can purchase in volume when pricing is favourable without risk of expiry, and can manage ink stock across longer planning horizons.

IC Chip Identification

Each Roland 750ml cartridge carries an integrated circuit (IC) chip that the printer reads upon insertion. The IC chip stores ink identity information — confirming the correct ink type, colour, and batch for the installed slot — and tracks remaining ink volume. This prevents accidental installation of an incorrect ink type in a slot (which can cause print quality failures or print head damage), and provides accurate ink level monitoring without manual measurement or estimation.

8Ink Configurations at a Glance

The IO-300 offers four ink configurations across the two ink families — three for EUV-HP and one for EUV-A7. Each configuration fills all eight ink slots with a combination of CMYK, White, Gloss, and Primer channels optimised for specific application priorities.

EUV-HP Configurations

Configuration 1: CMYKWhWhGlPr — The most versatile EUV-HP setup for operations that need both gloss effects and primer capability. Dual white ensures adequate white opacity for underbase applications. The Primer slot adds surface preparation capability for challenging substrates like glass, polycarbonate, and ceramic that benefit from a chemical adhesion-promoter layer before the colour print.

Configuration 2: CMYKWhWhGlGl — Prioritises maximum gloss/embossing capability with dual gloss slots alongside dual white. Best suited for operations focused on spot UV, embossing, and premium surface effects where the primer layer is not required. The dual gloss configuration doubles the available gloss ink supply for high-volume embossing work and can potentially enable greater embossing heights through more aggressive multi-pass strategies.

Configuration 3: CMYK×2 — Doubles all four CMYK channels for maximum production speed on pure colour jobs. This configuration sacrifices special effects and white capability entirely in favour of print throughput — ideal for high-volume CMYK output on rigid substrates where effects are not required and speed is the priority. Duplicate CMYK slots allow the printer to lay down higher ink volume per pass, effectively increasing print speed. For detail on how the IO-300 scales into mass production, see the guide to automation and production workflow.

EUV-A7 Configuration

EUV-A7: CMYKWhWhGlGl — The single available configuration for flexible-substrate printing balances CMYK colour, dual white for opaque underbase on dark materials, and dual gloss for spot and surface effects. This reflects the flexible-substrate market's typical application profile: colour printing on leather and fabric often requires white underbase on darker materials, and gloss effects are valued for premium presentation.

9Ink Consumption Reference

Understanding ink consumption at different quality modes and for different ink channels is essential for accurate job costing, production planning, and cartridge inventory management. The following data is measured at A2 size using EUV-HP ink, providing a consistent reference baseline. Two image types are measured: a standard N5A image (moderate ink coverage) and a dense N2A image (high ink coverage), reflecting the real-world variation between lighter and heavier print jobs.

Key Observations from Consumption Data

• CMYK consumption is remarkably consistent across quality modes — the difference between High Quality and High Speed 8P at N5A is only 0.04 ml per A2 sheet. This means quality mode selection is primarily a speed decision, not a significant ink cost driver for CMYK.
• White ink consumption dwarfs CMYK — at Standard White, a full A2 white layer uses 5.08 ml versus 0.77–0.78 ml for a full CMYK print. At White HD, the ratio rises to over 10:1 white:colour. Accurate job costing must account for white ink separately, not as part of a blended CMYK rate.
• Dual white slots are operationally necessary for white-intensive production — with white consumption at 5–8 ml per A2 sheet and a 750ml cartridge, a single white slot would need replacement approximately every 90–150 A2 sheets in full-coverage white workflows.
• Dense images (N2A) consume approximately double the CMYK ink of standard images (N5A) — reflecting the photorealistic/photographic versus solid-colour image distinction. This should be factored into estimates for jobs with heavy solid backgrounds or dense CMYK flood fills.