UV printing (flatbed and roll)

How it works

UV ink is a liquid acrylate that stays liquid in the head and hardens in a fraction of a second when UV LED lamps (usually 385–395 nm) beside the head pass over it. Nothing evaporates and no heat is needed, so it prints on heat-sensitive materials. Most machines print CMYK + white + varnish.

Typical uses

Acrylic signs and awards, wooden gifts, metal plates, glass, phone cases, pens, PVC and foam board, leather, packaging samples, tiles. Roll versions print banners, wallpaper and stickers.

Layer options

• White underbase for dark or transparent materials.
• Varnish: full gloss, spot gloss, or raised/embossed texture built up in layers.
• Reverse printing on clear acrylic: colour then white, viewed through the back.

Adhesion

• Porous materials (wood, leather) usually need no primer.
• Glass, metal, ceramics and smooth plastics need the correct primer first; test with a cross-cut tape test.
• Clean surfaces with IPA; fingerprints stop adhesion.

Hard vs flexible ink

Hard inks give better scratch resistance on rigid items. Flexible inks are needed for leather, PVC and anything that bends; hard ink cracks when flexed.

Safety and care

• Uncured UV ink irritates skin: always wear nitrile gloves; wash skin with soap, not solvent.
• Never look into the UV lamps; use the machine covers.
• Keep ink bottles closed and away from light.
• Use UV flush/cleaning fluid on UV heads – never water-based DTF cleaners.
• White UV ink still settles; use circulation and shake bottles.
• Stray light can cure ink on the nozzle plate; keep lamps shielded and clean the plate edges.

Common faults