Why Vectorr for UV Printing?
White Channel Preview: See exactly where white ink prints before sending to the RIP.
Spot Varnish Layer: Assign varnish to specific areas (text, logos, textures) as a separate channel.
Material Profiles: Load ICC profiles for acrylic, wood, metal, glass to preview color shifts per substrate.
UV Print Requirements
- Color Mode: CMYK + White (5-color or 6-color with light cyan/magenta). Some printers add Clear for spot varnish.
- Resolution: 600-1200 DPI for photographic quality, 300-600 DPI for signage.
- White Ink Channel: Required for transparent substrates (clear acrylic, glass) or dark materials (black aluminum, walnut).
- Spot Varnish: Optional clear coat applied to specific areas for gloss, matte, or texture effects.
White Ink Strategy
Transparent Materials (clear acrylic, glass): Print white first as a full underbase, then CMYK on top. White blocks the background from showing through.
Dark Materials (black metal, dark wood): Print white underbase only where CMYK sits to save ink and prevent cracking. Choke white 0.5mm to avoid halo.
Light Materials (white aluminum, birch plywood): Skip white entirely unless design includes light pastels that need opacity boost.
Flood White vs Spot White: Flood = full white rectangle under entire design. Spot = white only where needed (saves ink, prevents cracking on flexible materials).
Spot Varnish Workflow
Spot varnish (clear coat) adds gloss, texture, or matte finish to specific areas
- Create Varnish Layer: Duplicate the artwork layer, convert to grayscale.
- Define Varnish Areas: Black = full varnish, gray = partial, white = no varnish. Use selections to isolate text, logos, or textures.
- Assign to Clear Channel: Save varnish layer as a spot color named "Varnish" or "Clear" (RIP software maps this to the varnish channel).
- Layering: Varnish prints last (after CMYK + White). For raised texture, print multiple varnish passes.
Material-Specific Settings
Acrylic (clear or white): Print white first on back side for reverse-mount applications. Use second-surface printing to protect CMYK from scratches.
Wood (birch, walnut, bamboo): Grain absorbs ink unevenly. Increase ink density 10-15% and use wood-specific ICC profile.
Metal (aluminum, stainless): Requires primer or white underbase for color adhesion. Anodized aluminum holds UV ink directly.
Glass: White underbase mandatory. Print in reverse for second-surface applications (ink sits between glass and white layer).
Textured Surfaces: Increase ink laydown and reduce print speed. Use white underbase to fill texture and create smooth color surface.
Color Management
UV inks appear different on each material. Use ICC profiles to match screen preview to printed output
White Substrates (white acrylic, birch): Colors print close to screen RGB. Use standard CMYK profile.
Transparent Substrates (clear acrylic, glass): White underbase color affects final tone. Use profile designed for white-backed CMYK.
Dark Substrates (black aluminum, walnut): White underbase brightness determines color vibrancy. Test white density before production run.
Common UV Printing Issues
Ink Cracking: Too much white ink on flexible materials. Reduce white density or use spot white instead of flood white.
Color Shift: No material-specific ICC profile applied. Wood, metal, and acrylic all require different profiles.
Poor Adhesion: Material not prepped correctly. Some substrates need primer, flame treatment, or degreasing before printing.
White Halo: White underbase extends beyond CMYK edges. Choke white 0.5mm or use trapping in the RIP.
Varnish Streaks: Nozzle clog in clear channel. Run cleaning cycle before production.
File Output Specifications
Format: PDF with spot colors for white and varnish channels, or multi-page TIFF (one page per channel: CMYK, White, Varnish).
Color Space: CMYK for color channels, grayscale for white and varnish.
Bleed: 3-5mm beyond trim line for edge-to-edge prints.
Resolution: 600 DPI minimum for photo-quality, 1200 DPI for fine text.