UV Printing Guide
Complete UV Printing Process Guide: How to Use the IEHK A4 & A3 UV Flatbed Printer
Everything you need to go from blank substrate to a vibrant, durable UV print — setup, RIP software configuration, material prep, executing the print, and daily maintenance. Includes official IEHK video tutorials.
What is UV printing?
UV printing is a digital direct-to-substrate printing method that uses ultraviolet LED lamps to cure (harden) ink instantly as it is deposited onto a surface. Unlike solvent or aqueous printing, there is no drying time — the ink polymerizes on contact with UV light, which is why prints come out dry, vibrant, and scratch-resistant the moment the print head passes.
This makes UV printers ideal for small-run custom products, promotional items, and surfaces that normal printers cannot handle: glass, metal, wood, acrylic, leather, ceramic, and more — with no precoating or pretreatment required.
UV ink contains photoinitiators. When exposed to the UV LED lamp mounted directly behind the print head, these initiators trigger a chain reaction that instantly converts liquid ink into a hard, durable polymer layer bonded to the substrate surface.
Official IEHK A3 UV Printer demo video. For the full 17-video tutorial series, view the complete playlist on YouTube ↗
IEHK A4 vs A3 UV Printer — which should you choose?
IEHK offers two compact UV printer sizes. Here is a head-to-head comparison to help you pick the right model for your business.
Entry level
IEHK A4 UV Printer
- Print area 300 × 200 mm
- Max resolution 5760 × 1440 DPI
- Rotary platen Yes (bottles)
- Max object height 150 mm
- Ink channels 6 cartridges
- Best for Gifts, phones, pens
Most popular
IEHK A3 UV Printer
- Print area 420 × 297 mm+
- Max resolution 5760 × 1440 DPI
- Rotary platen Yes (bottles)
- Max object height 150 mm
- UV DTF mode Yes (2-in-1)
- Best for Signs, boards, larger items
If you print primarily phone cases, small gifts, pens, or golf balls, the A4 is the most cost-effective entry point. If you also need to print wood signs, A3 sheets, or larger promotional products — or want UV DTF transfer capability — choose the A3.
Compatible materials — what can you print on?
One of the biggest advantages of IEHK UV printers is the enormous range of substrates they support without any pretreatment or precoating.
UV flatbed printers are designed for hard, rigid surfaces. They do not print well on highly uneven, textured, or fabric surfaces. For T-shirts and garments, use a DTG printer instead. The IEHK A3 UV printer also has a UV DTF mode for creating transfers that can be applied to soft materials.
Step 1 — Hardware setup & installation
Before printing anything, you need to properly set up the printer, install ink, and initialize the system. This takes approximately 30–60 minutes on first setup.
Unbox and position
Place the printer on a flat, stable surface. Remove all packaging foam and tape — including internal packing materials around the print head carriage. Ensure there is at least 20 cm of clearance on all sides for ventilation and media handling.
Connect power and USB
Connect the power adapter and the USB cable to your Windows 10 (or later) computer. Do not power on yet — install the driver and RIP software first. IEHK printers are compatible with Windows 10 and Windows 11.
Install ink cartridges
Open the ink bay and insert the CMYK + White + Varnish cartridges in the correct slots (marked with labels). Shake the white ink cartridge gently before installing — white UV ink settles and must be mixed before use. Press each cartridge firmly until it clicks.
Initial ink fill / prime
Power on the printer. It will automatically begin an initial ink fill sequence to prime the lines. This takes 5–10 minutes. Do not interrupt it. The printer will prompt on-screen or in the driver when complete.
IEHK A3 UV Printer hardware and printing demonstration. Full tutorial playlist ↗
Step 2 — Installing and configuring RIP software
RIP (Raster Image Processor) software is the bridge between your design file and the printer. The IEHK UV printer comes with a professional RIP software package that handles color management, white ink layers, print modes, and job queuing.
Installation steps
- Insert the included USB drive or download the RIP software from IEHK support.
- Run the installer as Administrator on Windows 10/11.
- Follow the on-screen steps — accept the license, choose install directory.
- When prompted, select your printer model (A4 or A3 UV) and connection type (USB).
- Complete installation and restart your computer.
- Open the RIP software and run Printer Setup / Test to confirm communication.
| Feature | What it does |
|---|---|
| Color management | ICC profile control for accurate CMYK reproduction on each substrate type |
| White ink layer | Automatically generates white underbase or highlight layer for dark/transparent substrates |
| Varnish layer | Generates a spot varnish pattern for 3D texture effects and surface protection |
| Print mode | Select Draft / Standard / High Quality — controls pass count and resolution |
| Nozzle check | Prints a test pattern to confirm all nozzles are firing correctly before a job |
| Job queue | Line up multiple print jobs, track status, repeat previous jobs |
Never print directly from Adobe Illustrator, Photoshop, or Word. The RIP software handles proper color conversion, white ink generation, and print head passes that standard printer drivers cannot do. Skipping RIP will result in poor color accuracy and missing white ink layers.
Step 3 — Preparing your artwork
Proper file preparation is critical for UV printing quality. Follow these guidelines before sending any job to the RIP software.
File format and color mode
Save your artwork in PDF, TIFF, or high-resolution JPEG/PNG format. Use CMYK color mode for the most accurate color output. If you design in RGB (Photoshop, Illustrator), convert to CMYK before exporting and check for color shifts — especially in saturated blues and greens.
Resolution
Set artwork resolution to 300 DPI minimum at the actual print size. The IEHK UV printer can output up to 5760 × 1440 DPI, but the input file resolution is the ceiling for detail quality. Low-resolution files will print visibly blurry.
White ink layer (for dark or transparent substrates)
When printing on dark materials (black wood, dark glass, colored metal) or transparent materials (clear acrylic, glass), you need a white ink underbase to make colors opaque and vibrant. In most RIP software:
- Create a separate spot color layer named
Whitein your design file. - Fill this layer with solid white in the exact shape you want opaque.
- The RIP software will map this layer to the white ink channel automatically.
Varnish / texture layer (optional)
For raised 3D texture, glossy spot UV, or matte areas, create a spot color layer named Varnish. The RIP software will print additional clear UV ink passes over these areas, building up a tactile texture.
Forgetting to add a white ink underbase on glass or dark acrylic is the #1 beginner error. Without white ink, CMYK colors are nearly invisible on non-white surfaces because UV inks are semi-transparent by nature.
Step 4 — Preparing the substrate
Even though IEHK UV printers require no precoating, the substrate surface must still be clean, dry, and flat for consistent ink adhesion.
Clean the surface
Wipe the print surface with isopropyl alcohol (IPA) 70–99% and a lint-free cloth. Remove all dust, oils, fingerprints, and residue. Even invisible oils from skin contact will cause ink adhesion failures. Allow the surface to dry completely (30–60 seconds) before printing.
Check flatness
UV flatbed printers require a flat, even surface. Slight warping or uneven thickness causes inconsistent print head height, leading to blurry edges or ink splatter. For wood, ensure it is fully flat — use a light clamp or tape edges if necessary.
Set platen height
The IEHK UV printer features a motorized up/down platform with auto height detection. Place your substrate on the platen, then use the height adjustment function (button or auto-detect) to set the correct gap between print head and surface. The optimal gap is typically 1–2 mm.
Position and align
Use the registration guides or the printer’s alignment grid to position your substrate consistently. For repeat jobs, mark a registration corner with tape. For cylindrical objects (bottles, cups, pens), attach the Rotary Platen accessory and position the item in the rotary cradle.
IEHK A3 UV Printer printing on a metal box — substrate setup and height adjustment in practice. Full tutorial playlist ↗
Step 5 — Configuring print settings in RIP software
Before sending a job, configure these key parameters in the RIP software based on your substrate and quality requirements.
| Setting | Recommended value / guidance |
|---|---|
| Print mode | Draft (1–2 passes) for proofs; Standard (4 passes) for production; High Quality (8+ passes) for fine art or photography |
| Resolution | 720 × 720 DPI for draft, 1440 × 1440 DPI for standard production, 2880+ DPI for maximum detail |
| White ink mode | Underbase for printing on dark/transparent materials; Highlight for special effects on clear substrates; Off for white substrates |
| Color profile | Select the ICC profile matching your substrate type (e.g. “Acrylic,” “Metal,” “Wood”) for the most accurate color |
| Print direction | Bidirectional is faster; Unidirectional is slower but avoids banding artifacts on very fine detail |
| UV lamp power | Full power for all standard materials; reduce for heat-sensitive materials (thin film, some plastics) |
Step 6 — Executing the print job
With the file prepared, settings configured, and substrate in place, you are ready to print.
Run a nozzle check
Always print a nozzle check pattern before starting any job — especially after the printer has sat idle overnight. In the RIP software, go to Maintenance → Print Nozzle Check. Inspect the printed pattern: all lines should be clean and unbroken. If lines are missing, run 1–2 head cleaning cycles before continuing.
Load the job & preview
In the RIP software, import your prepared file and use the print preview to verify position, size, and color layers. Confirm the white ink layer and varnish layer (if any) appear correctly. Set the print origin to match where your substrate is positioned on the platen.
Send to printer
Click Print. The RIP software will process the file (rasterize) and send data to the printer. The print head will begin its first pass. Watch the first pass closely — if ink is placing incorrectly or the head height seems wrong, pause and correct before continuing.
UV curing happens automatically
As the print head moves, the UV LED lamp directly behind it cures ink instantly. By the time the print head completes the final pass, the print is dry and hard to the touch. You do not need to wait — prints are ready to handle immediately after printing completes.
IEHK A3 UV Printer — User Manual Series (17 videos)
Covers printing on wood, glass, metal, acrylic, phone cases and more
Official IEHK tutorial playlist — printing on wood, glass, acrylic, metal and other hard materials.
Step 7 — Post-print finishing & quality inspection
UV ink is immediately cured after printing — there is no waiting time. However, there are post-print steps to ensure the best quality and durability.
Quality inspection checklist
- Check for color accuracy — compare to your on-screen design under good lighting.
- Inspect edges for clean, sharp boundaries. Fuzzy edges usually indicate incorrect head height.
- Check white ink coverage — look for gaps in the underbase on dark substrates.
- Test scratch resistance — gently drag a fingernail over the print. Properly cured UV prints do not scratch.
- Inspect for banding (horizontal lines) — if present, a head cleaning or print mode adjustment is needed.
Adding a varnish topcoat (optional)
For maximum durability and a premium finish, you can run the print through a second varnish-only pass. This adds an extra hard UV coating over the entire printed area, improving scratch resistance and UV stability for outdoor applications.
IEHK UV ink is fade-resistant, scratch-resistant, and waterproof. Prints are suitable for both indoor and outdoor use. For extended outdoor exposure, an additional UV varnish topcoat is recommended for maximum longevity.
Bonus: Printing on bottles & cylindrical objects (Rotary mode)
Both the A4 and A3 IEHK UV printers include a Bottle Rotary Platen accessory that allows printing on round objects such as bottles, mugs, cups, pens, USB drives, and golf balls.
| Spec | Value |
|---|---|
| Compatible diameter | 20–110 mm (A4) / 50–110 mm (A3) |
| Max object length | 200 mm (A4) / 320 mm (A3) |
| How it works | Object rotates on the platen as the print head moves, wrapping the image around the cylinder |
| Setup | Attach rotary cradle, measure diameter, enter value in RIP software for correct scaling |
Daily maintenance routine
UV printers are precision instruments. Regular maintenance prevents costly nozzle clogs, especially with white ink (which settles quickly) and ensures consistent output quality over years of use.
Daily — before printing
Print a nozzle check pattern. Run 1 head cleaning cycle if any nozzles are missing. Shake (or agitate via the white ink circulation system) white ink before use. Wipe the platen surface clean.
Daily — after printing
Run the capping sequence (the printer does this automatically on shutdown) to seal the print head nozzles. Never leave the printer powered off with the caps open — exposed nozzles dry out and clog within hours.
Weekly
Clean the capping station and wiper blade with lint-free swabs and cleaning solution (provided). Inspect ink lines for air bubbles. If the printer is not used for more than 3 days, print a nozzle check on restart and clean if needed.
Monthly
Perform a full deep cleaning of the print head area. Check UV LED lamp output (reduced output means longer cure times and potential under-curing). Replace ink cartridges when prompted — do not run cartridges completely dry.
White UV ink pigment is heavy and settles quickly. The IEHK A3 UV printer includes a White Ink Circulation System that automatically agitates the white ink channel to prevent settling and clogging — make sure this is enabled in settings.
Frequently asked questions
Do I need to precoat or prime my substrate before UV printing?
No. IEHK UV printers use ink formulas that bond directly to most rigid surfaces without any precoating or pretreatment. This is one of their key advantages over aqueous inkjet printers. The only requirement is a clean, dry surface.
How long does a UV print take?
A single A4-size print at standard quality (4 passes) typically takes 1–3 minutes. High-quality mode with white ink layers takes 4–8 minutes. Prints are fully dry and scratch-resistant immediately after the print job completes — no waiting required.
Can the IEHK A3 UV printer print on T-shirts?
Not directly. UV flatbed printers print on hard, rigid surfaces. For T-shirts and garments, you need a DTG (Direct-to-Garment) printer. However, the IEHK A3 UV also has a UV DTF (Direct-to-Film) mode — you can print a transfer on special UV DTF film, then apply it to garments using heat and pressure.
What computer and OS is required?
IEHK UV printers require a computer running Windows 10 or Windows 11. The RIP software is Windows-only. A USB connection is used — ensure your PC has a USB-A port or use a hub. Recommended: at least 8 GB RAM and a modern multi-core processor for fast RIP processing.
How long do UV prints last?
IEHK UV prints are fade-resistant, scratch-resistant, and waterproof. For indoor use, prints maintain color quality for 5+ years. For outdoor applications, adding a UV varnish topcoat significantly extends longevity. The hard polymer UV ink layer is far more durable than water-based inkjet or toner prints.
What should I do if the print has banding (horizontal lines)?
Banding is usually caused by clogged nozzles. Run a nozzle check, identify which channels are missing, and perform 1–2 head cleaning cycles. If banding persists, switch from bidirectional to unidirectional print mode, or increase the pass count. Persistent banding after multiple cleanings may indicate a partially blocked print head requiring deeper maintenance.
Ready to start UV printing?
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