Prep → UV printing

UV printing: white ink and varnish in the file.

UV printing white ink and varnish: spot swatches above the colour, 300 dpi at final size, UV-DTF line minimums of 0.3 to 0.6 mm: what makers and RIPs ask.

Sources read 2026-10-21 · updated 2026-10-26 · next re-read due 2027-01-19

On this page

How the process treats your file

A UV job is a CMYK image plus extra ink channels. ONYX separates a file into process inks and specialty channels (white, gloss or varnish, primer, structural), and Roland’s VersaWorks 7 lists white, gloss, primer, metallic silver and structural as spot inks (ONYX, Roland VersaWorks 7).

Vector PDF or EPS files carry named spot swatches (RDG_WHITE, White or Varnish, Spot1) placed above the process objects, and ONYX and Epson/Grimco want overprint on them. TIFF jobs use alpha or extra channels instead (ONYX, Epson/Grimco, Caldera).

Without prepared channels, Mimaki’s Valid Pixel mode and Caldera’s Generate from CMYK data build the white plate from non-zero pixels; Caldera calls its version suited to experiments (Mimaki, Caldera).

UV-DTF adds a film step. PNW Print Co says its RIP makes the white layer slightly smaller than the design (choke) and the clear varnish slightly larger, and asks for 0.2 to 0.25 in between designs because the varnish overlaps the print edges (PNW Print Co).

Printful’s general file guide and Gelato’s phone-case page ask for PNG or JPEG at Printful and PNG or PDF at Gelato, at 150 to 300 dpi; neither mentions spot channels (Printful, Gelato).

What the printers specify

Flatbed media runs from 210 x 297 mm on the Epson V1070 (Epson V1070) to 2,500 x 1,250 mm on the SC-V7000 (Epson SC-V7000). UV-DTF sheets are set by the shop: 23 in wide at PNW Print Co (PNW Print Co), 11 in wide at UV DTF Prints (UV DTF Prints). Ask for the bed or sheet size before you build.

Resolution at print size

The three sources in this row that cover UV work ask for 300 dpi at final size: Gelato’s phone-case page, Prodigi’s clear-case sheet and Long Island DTF Printing’s file guide (Gelato, Prodigi, Long Island DTF Printing). If you do not know the printer, build raster art at 300 dpi at final print size. The platform-wide figures below do not name UV, and the printer figures are output resolutions, not file floors.

File format

Gelato and Prodigi, the two platform pages here that name UV flatbed work, ask for PNG or PDF; Long Island’s DTF and UV DTF guide prefers PNG (Gelato, Prodigi, Long Island DTF Printing). The RIPs split by method: Mimaki’s colour replacement needs vector data in ps, eps or pdf (Mimaki), while ONYX and Caldera read an alpha channel from a TIFF (ONYX, Caldera).

Colour mode and profile

The sources split. ONYX says design in CMYK or convert to it (ONYX); Loostra converts uploads to CMYK itself (Loostra); Printful and Printify, for all their products, ask for RGB (Printful, Printify). Ask the printer, and strip an embedded profile from a PDF bound for Mimaki colour replacement (Mimaki).

Transparency and alpha

Gelato says transparent areas are not printed but any pixels in them get a white underlayer with the colour (Gelato); PNW says translucent areas are incompatible with UV-DTF (PNW Print Co). Epson/Grimco ties the opacity of a spot colour to ink density (Epson/Grimco).

  • ONYX (RIP): for TIF files the custom channel can represent an alpha channel, and a detected alpha channel is assigned automatically to a specialty ink channel — ONYX: Designing with white specialty ink
  • ONYX (RIP): objects with overprint are not rendered when transparency is present; a separations PDF resolves the conflict — ONYX: Designing with white specialty ink
  • Epson SureColor V-Series / Grimco (maker | RIP): listed as not a requirement but as something that changes the output: the transparency of the colour dictates the ink density; a spot colour at 70% opacity lays down 70% ink density — Epson/Grimco: V-Series best practices
  • Gelato (platform; phone cases, UV printing paragraph): transparent areas are not printed, but any pixels in those areas get an underlayer of white ink with the colour ink — Gelato: Optimizing print results for phone cases
  • PNW Print Co (platform; DTF and UV DTF page): neon glow, drop shadows, translucent areas and soft or fading edges may not print well because of the white underbase, and the page calls them “completely incompatible with UV DTF”; remove them before submitting — PNW Print Co: DTF and UV DTF artwork requirements

UV printing white ink and varnish: white and varnish channels

Each RIP finds white and varnish by its own spot names, or builds the plate itself. Ask which one the printer runs before you name a swatch.

Layer order and white position

Put the spot objects above the process objects in the file; ONYX says the print layer order is then set in its RIP or on the printer. On the Epson V1070, white goes first or later in the layer order, depending on the media and the viewing side.

Minimum line and text size

The figures here come from UV-DTF shop pages, and two of those pages cover DTF and UV DTF together. Lines run from 0.3 mm at Loostra for hard goods (Loostra) to 0.025 in (0.6 mm) at PNW Print Co (PNW Print Co); text is 6 pt and up at UV DTF Prints and Loostra (UV DTF Prints, Loostra). Without a printer’s own number, draw lines at the thicker end.

Bleed, wrap and safe zone

No shared bleed figure turns up. Long Island says UV transfers need none (Long Island DTF Printing); Gelato wants phone-case art to cover the case including bleed (Gelato). Use the printer’s template where there is one.

  • Long Island DTF Printing (platform; DTF and UV DTF guide): bleed “None required”; DTF and UV transfers are cut to the artwork edge, no trim needed — Long Island DTF Printing: File requirements
  • Gelato (platform; phone cases): make the artwork large enough to cover the whole case including the bleed area, and keep critical text and logos away from the edges and camera apertures — Gelato: Optimizing print results for phone cases
  • Printful (platform; phone cases, print method not stated on the page): 300 DPI recommended; extend artwork to the full print area including bleed; keep text in the safe area; PNG or JPEG — Printful: How to make phone cases
  • Prodigi (platform; all print-on-demand products, process not stated): download the product template, which outlines how much of the image is used as bleed — Prodigi: Image requirements FAQ
  • Mimaki Kebab (maker, rotary attachment): paste the mark tape where there is no print data; print data under the tape position may cause false recognition — Mimaki: How to, Easy name printing (UJF + Kebab + RasterLink6)
  • Mimaki Kebab HS (maker | RIP, rotary attachment): on tapered objects the print area compresses from the large to the small diameter; the RasterLinkTools tapered shape function corrects the warp — Mimaki: Kebab HS brochure
  • Roland VersaWorks (maker | RIP): not every substrate is flat; the Generic Distance mode slows the print head and fires larger droplets for slightly uneven substrates, and the height variance should stay within a couple of millimetres — Roland DG: UV printing tips for VersaWorks

Ink and colour limits

Limits here are RIP and test findings, not shared file rules. The one file-side count in these sources is ONYX’s limit of 12 separations in a separations file (ONYX).

  • ONYX (RIP): separation files are limited to 12 separations (process plus extended gamut plus spot); above that, use a composite file — ONYX: Designing with white specialty ink
  • Mimaki RasterLink7 (maker | RIP): ink density defaults to 100%; special plate jobs become mono-colour solid special colour data and ignore the density of the original image — Mimaki: RasterLink7 reference guide, Special plate - Operations
  • Mimaki RasterLink7 (maker | RIP): density cannot vary within a single special colour job; for gradations, create the special colour image data and set the special colour ink as the page describes for monotone jobs — Mimaki: RasterLink7 reference guide, Special plate - Operations
  • Mimaki RasterLink7 (maker | RIP): density must be at least 1% for objects subject to colour replacement; white objects at C=0 M=0 Y=0 K=0 or at 0% density may give unintended replacement results — Mimaki: RasterLink7 reference guide, Color Replacement - Functions
  • Epson SureColor V-Series / Grimco (maker | RIP): if the workflow includes cutting, routing or punching, test results favour a single white, single colour and single varnish layer; the test was an SC-V7000 on PVC (Mactac IMAGIN JT 5829R) and Lintec E1000ZC film, with the punch-out checked for cracks — Epson/Grimco: V-Series best practices
  • CalderaRIP / Epson SC-V7000 (RIP): “Fine” qualities are not compatible with Varnish spot ink; a print-mode limit in the RIP, not a file rule — Caldera: EPSON SureColor SC-V7000 print module interface
  • Durst P5 X (maker; large-format flatbed and roll printer): 10 colour channels, which can combine CMYK, white, fluo glow, orange, violet, light cyan, light magenta, light black, varnish and primer; a hardware configuration, not a file limit — Durst: P5 X

Gloss, varnish and primer

At Roland, a gloss layer is a spot layer named RDG_GLOSS, converted to greyscale (Roland DG); Mimaki sets glossy and matte through irradiation settings (Mimaki).

Raised and textured prints

Canon’s PRISMAelevate XL builds height from layers of about 50 µm each (Canon). Its brochure gives Brila 18 layers and 0.25 mm, Alto 36 layers and 1 mm, Alto-Plus 54 layers and 2 mm (Canon brochure); release 2.1 raises the height to 4 mm (Canon Graphiplaza). Layer height per mode is not stated, and layer counts times 50 µm (Canon) do not reproduce the brochure’s heights, so take heights from the brochure (Canon brochure).

  • Canon PRISMAelevate XL (maker | RIP): multiple very thin ink layers are printed on top of each other, each cured with UV light, until the elevation is reached; one layer is about 50 µm, and a white cover layer and a full-colour layer go on top — Canon: How Canon elevated printing technology works
  • Canon PRISMAelevate XL (maker | RIP): Alto, opaque elevation plus colour, textured printing up to 1 mm, 36 layers maximum, elevation built with all colours or white only; varnish in the elevation reduces tension build-up (when available) — Canon: PRISMAelevate XL brochure
  • Canon PRISMAelevate XL (maker | RIP): Alto-Plus, opaque elevation plus colour, textured printing up to 2 mm, 54 layers maximum, layers of dark ink, mold mode for speed — Canon: PRISMAelevate XL brochure
  • Canon PRISMAelevate XL (maker | RIP): Brila, transparent elevation up to 0.25 mm, 18 layers maximum, varnish on top of the colour image layer, optional white undercoat — Canon: PRISMAelevate XL brochure
  • Canon PRISMAelevate XL 2.1 (maker | RIP): “doubles the printing height to 4 mm (0.157”)”; the brochure predates release 2.1, and its top mode, Alto-Plus, stops at 2 mm (Canon brochure) — Canon Graphiplaza: PRISMAelevate XL
  • Roland DG (maker | RIP): embossing lays down multiple layers of matte varnish with a gloss finish on top, and the number of layers is set in VersaWorks — Roland DG: UV printing tips for VersaWorks
  • Mimaki RasterLink7 (maker | RIP): Emboss Print overlays clear ink multiple times, and the ink does not cure by the irradiation during printing alone, so additional UV irradiation is needed — Mimaki: RasterLink7 reference guide, Properties - Operations

UV-DTF film: choke, bleed, spacing and cut lines

The pages read for this row are PNW Print Co, UV DTF Prints, Printify and Roland. Only PNW describes the white choke and the varnish bleed, and it describes its own RIP, not every shop’s (PNW Print Co).

Textile DTF film chokes its white layer the same way: see DTF: White handling.

Where the sources disagree

Spot names are per RIP

Roland names the spot swatches RDG_WHITE and RDG_Gloss (Roland VersaWorks 7). Epson Edge Print wants “White” or “Varnish” with capital first letters and correct spelling (Epson/Grimco). ONYX assigns by name and asks for Spot1, Spot2 and so on; other names need extra steps in the RIP (ONYX). Roland also spells the gloss swatch RDG_Gloss in VersaWorks 7 and RDG_GLOSS in VersaWorks 6 and on its blog (VersaWorks 6, Roland blog).

On the floor: a file named for one RIP has to be renamed for another. ONYX’s other routes are Spot Channel Replacement in ProductionHouse or Thrive, or a separations PDF (ONYX).

Minimum line for UV-DTF

Loostra asks for 0.3 mm (0.85 pt) on hard goods, and 0.5 mm for textile and DTF lines (Loostra). Long Island asks for 1.5 pt (0.53 mm) on a DTF and UV DTF guide (Long Island DTF Printing). PNW Print Co asks for 0.025 in (0.6 mm, 1.8 pt), also on a DTF and UV DTF page (PNW Print Co).

On the floor: the minimums differ by shop. PNW says thinner parts may not get the white under-layer or adhesive and can fall off the film (PNW Print Co). A 0.3 mm line passes Loostra and fails PNW. Loostra’s own page says a 0.3 mm line is 1.5 pixels at 300 DPI; that arithmetic is wrong, as 0.3 mm is about 3.5 px (Loostra).

What fails on the floor

No case below comes with a photo or the file’s properties; all are text descriptions from the maker’s or shop’s own page.

Spot colour knocks out the design underneath

Symptom: the white or varnish area cuts a hole through the colour design under it. Cause in the file: the White or Varnish spot swatch is not set to Overprint Fill or Overprint Stroke in Illustrator. “If the spot color is not set to “Overprint Fill” or “Overprint Stroke”, then the spot color will cut through the design under the spot color” — Epson/Grimco: V-Series best practices

Specialty ink missing inside a transparency box

Symptom: white or varnish does not print in some regions. Cause in the file: an EPS where a spot object crosses a transparency bounding box; the box is rasterized and the specialty ink does not print there. The remedy per the source is a PDF of version 1.4 or higher — ONYX: Designing with white specialty ink

White and metallic swapped

Symptom: white ink prints where metal is expected and the other way round. Cause in the file: a separations PDF whose spot names are not Spot1, Spot2; Illustrator lists spots alphabetically (Metal before White), so ONYX maps them to the wrong channels until Color Order is set to Custom. “If the default options are used, white ink will print where metal is expected and metal will print where white is expected.” — ONYX: Designing with white specialty ink

Spot colour ignored or garbled in RasterLink7

Symptom: colour replacement does not run, the spot name shows as garbled characters, or the job will not import. Cause in the file: a PDF saved with an embedded profile, a spot name with multi-byte or non-alphanumeric characters, or a white vector object set to C=0 M=0 Y=0 K=0 or 0% density. “The density must be set to a minimum of 1 % for objects subject to color replacement.” — Mimaki: RasterLink7 reference guide, Color Replacement - Functions

Solid block under a transparent TIFF

Symptom: the special-colour plate covers the whole rectangle of a placed TIFF instead of its shape. Cause in the file: a transparent TIFF placed into an illustration and exported as EPS or PS instead of PDF, so the TIFF rectangle is treated as the data portion — Mimaki: RasterLink7 reference guide, Special plate - Operations

Tactile varnish spreads past its target

Symptom: a tactile print spreads or oversprays past the intended target. Cause: too much ink density, or too many ink layers, which make white or varnish spread. The listed remedy is to decrease varnish amount or density, starting at 65% and increasing as needed — Epson/Grimco: V-Series best practices

Cracks when printed sheets are routed or punched

Symptom: cracks in the punched part. Cause in the file: stacked layers of white and colour. In Epson’s test (SC-V7000, PVC and Lintec E1000ZC film, punch-out checked for cracks) multi-layer white plus colour failed; Epson advises one white, one colour and one varnish layer for cut, routed or punched work — Epson/Grimco: V-Series best practices

Fine details fall off the film or do not transfer

Symptom: thin lines or parts of letters come off the film before pressing. Cause in the file: parts thinner than 0.025 in (0.6 mm, 1.8 pt), which may not get the white under-layer or adhesive (PNW, DTF and UV DTF page). “Lines or parts of letters that are too thin may fall off the film before you have a chance to press the transfer.” — PNW Print Co: DTF and UV DTF artwork requirements

Rotary sensor misreads the mark tape

Symptom: false recognition of the optical mark on a rotary attachment. Cause in the file: print data at the position where the mark tape is read. “If there is print data at the position where the mark tape is read, false recognition may result.” — Mimaki: How to, Easy name printing (UJF + Kebab + RasterLink6)

What shops ask on the forums

Three file questions came up in at least two threads since 2024. The quotes are the askers’ opening posts; replies are not used, and not every asker names UV. The third question rests on two consumer-printer threads and is the thinnest of the three.

“How do I put white or varnish into the file so the RIP reads it as a channel?”

“I’m really not sure how to setup the white or clear spots on this so I can test them.” — Forum: Onyx and UCJV330 Config, November 2025. The asker runs a Mimaki UCJV330 through ONYX. Also asked in Forum: KingJet 6090 UV flatbed – full varnish coverage uneven, January 2026, where the asker built spot channels in Photoshop, saved a TIFF and says “Looks like the RIP is reading the photo brightness instead of treating the spot channel as solid 100% varnish”. A later reply from the asker says fixing the channels solved it.

What our sources say: swatch names per RIP, RDG_WHITE and RDG_Gloss at Roland DG, “White” and “Varnish” at Epson/Grimco, Spot1 and Spot2 at ONYX, “Use a Spot Color” at Caldera. A TIFF or PDF keeps named spot channels, a PNG or JPG does not (DTF Transfer Studio), and Roland’s gloss layer is greyscale from zero to 100% (Roland DG). None says how to save a spot channel in Photoshop, whether a varnish channel should be solid rather than a density map, how a Mimaki UCJV is set up in ONYX (the guide’s Mimaki rows are RasterLink7 only), or anything about Hosonsoft.

“Why does my white or varnish knock out the colour, and which layer goes on top?”

“The printer is still avoiding dropping ink overtop the text. What am I missing?” — Forum: Onyx - White Overflood Layer Stack, May 2026. The asker puts a white Spot1 layer above the colour layer in Illustrator for a second-surface print on a flatbed; UV is not named in the thread. Also asked in Forum: I want to print UV on transparan sticker … How do I set this spot channel on photoshop?, October 2025, where the asker puts CMYK at the bottom and white on top for the inside of a glass door and reports “But the print out is just only full white. No CMYK colors printed. Is there a way to make this?”

What our sources say: spot objects sit above the process objects (ONYX); a spot colour not set to Overprint Fill or Overprint Stroke “cuts through the design under it” (Epson/Grimco); on the Epson V1070 white is the first layer as an underbase, or the second layer, with the image oriented for the non-printed side, when the film is viewed from the other side (Epson). The Reddit post names no RIP, so which of these applies to it is our inference, not a source’s statement.

“How do I make a raised or textured print from a file, and how thin can it go?”

“Are there printers, or techniques (multiple flat layers??) that can create the thinner raised areas?” — Forum: Watch Dial and Thin Layers, October 2026. The asker wants thinner relief than a consumer printer’s minimum emboss and is also comparing printer specs. Also asked in Forum: Is “3D” UV printing an open standard?, August 2026: “Is this “3D” depth thing something UV printers have always been able to do? How would one set it up if so? Thousands of layers?” Both askers use consumer machines.

What our sources say: Canon’s PRISMAelevate XL builds height from layers of about 50 µm each (Canon), with Brila at 18 layers and 0.25 mm, Alto at 36 layers and 1 mm, Alto-Plus at 54 layers and 2 mm (Canon brochure). Roland embosses with multiple layers of matte varnish, the count set in VersaWorks (Roland DG); Mimaki’s Emboss Print overlays clear ink and needs additional UV irradiation (Mimaki). None says how to author the height in the file for a given RIP, covers anything thinner than the 0.25 mm of Brila, or addresses consumer printers.

Preflight before you upload

  • Ask which RIP runs the job and name white and varnish swatches for it: RDG_WHITE or RDG_Gloss for Roland, White or Varnish for Epson, Spot1 and Spot2 for ONYX — Roland, Epson/Grimco, ONYX
  • Spot names for Mimaki use single-byte alphanumeric characters only — Mimaki
  • Spot objects sit above the process objects, with Overprint Fill or Overprint Stroke set — Epson/Grimco, ONYX
  • No spot object crosses a transparency box in an EPS; use PDF 1.4 or higher — ONYX
  • A transparent TIFF going to RasterLink7 is saved as PDF, not EPS or PS — Mimaki
  • A PDF for Mimaki colour replacement is saved without an embedded profile — Mimaki
  • White vector objects have density of at least 1%, not C=0 M=0 Y=0 K=0 — Mimaki
  • A separations PDF for ONYX names spots Spot1, Spot2, or Color Order is set to Custom, and stays within 12 separations — ONYX
  • Raster art is at 300 dpi at final print size unless the printer states another figure — Gelato, Prodigi
  • UV-DTF lines are at least 0.3 mm to 0.6 mm depending on the shop, and text is 6 pt or larger — Loostra, PNW Print Co, UV DTF Prints
  • Glows, drop shadows, translucent areas and soft edges are removed from UV-DTF art — PNW Print Co
  • A UV-DTF gang sheet leaves at least 0.2 to 0.25 in between designs and fits the shop’s sheet width — PNW Print Co, UV DTF Prints
  • Work that will be cut, routed or punched uses one white, one colour and one varnish layer — Epson/Grimco
  • On rotary work, no artwork sits under the mark tape position — Mimaki

Sources, checked on 2026-10-21

Forum threads

Could not check

  • signs101.com operator forum threads on UV flatbed white and varnish registration failures: blocked (HTTP 403 bot wall).
  • canon-cna.com Canon North America product specification pages: blocked (HTTP 403); Canon’s Graphiplaza and brochure pages were read instead.
  • helpdesk.caldera.com, help.printful.com and help.printify.com article HTML: 403 to the fetcher, so the articles were read through the help centres’ public Zendesk API and are cited by their article address.

Seen a spec here that is wrong, or that a printer has changed? Send it with the printer's page through the nozzle check →