Production guide · 6 min read
How to check a DTF file before printing
Five checks that catch most DTF problems before film is wasted: print size and resolution, real transparency, semi-transparent pixels, thin lines and the white layer.
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Most failed DTF transfers trace back to the file, not the printer: too few pixels for the transfer size, a background that only looks transparent, soft shadows that print as specks, or lines too thin to survive on film. Five checks catch most of them before anything is printed.
Check resolution at the transfer size
Decide the printed width first, then divide the image’s pixel width by that width in inches. A 3,000-pixel design printed 10 inches (25.4 cm) wide has 300 effective PPI; at a full-front 12 inches it has 250. Many DTF shops ask for about 300 PPI at final size, but follow your own shop’s rule. The effective PPI guide explains the calculation and its limits, and Adobe notes that enlarging a placed image lowers its effective resolution.
Confirm the background is really transparent
DTF prints everything that is not transparent, including a white background that is invisible on a white screen. Open the file against a dark and a checkerboard background. A JPG cannot hold transparency at all, so a “transparent” JPG is always a filled rectangle. Ask for a PNG with a real alpha channel, or remove the background yourself; the DTF background guide covers masks and edges.
Find semi-transparent pixels
Drop shadows, glows, feathered edges and anti-aliased fringes contain pixels that are partly transparent. On film they usually print as a pale halo, white specks or a muddy outline, because the white layer underneath cannot be half there. Zoom in to 200–400% on the edges, or use a check that counts pixels between fully transparent and fully opaque. Either remove the soft effect or turn it into solid pixels before printing.
Check thin lines and small text
Very fine strokes and small serif text can break up or peel after pressing. A common working minimum is around 0.25 mm at the printed size, though film, powder and garment change that. Measure lines at final size, not at screen zoom. Thicken strokes, simplify fine texture, or print the design larger if detail matters.
Review the white layer and proof
The RIP generates the white underbase from the file. Roland describes DTF artwork as a transparent PNG processed with a white layer in the RIP. Check the RIP preview for white showing past the colour edge, holes that should stay open and fine details that disappear. For a new design style or an uncertain edge, press a small proof on the intended garment colour before running a full gang sheet.
Which software you need
A DTF workflow usually has two kinds of software. A RIP drives the printer, handles colour and generates the white layer. File preparation software comes before it: it checks and fixes customer artwork and lays designs out on a gang sheet. Endorr is file preparation software. It starts free (Studio Free, 49 tokens a month, no card), and checking a file never costs tokens; removing a background costs 10 tokens and an upscale 20. Paid plans start at Studio, $15 / €14.95 a month (excl. VAT in Europe). The gang sheet builder for your own store is an optional add-on. See pricing for the full list, and how it compares with DTF Roll Studio, DTF Toolbox and DTF Transfer Studio. Building sheets by hand? Follow how to build a gang sheet.
Technical references
Check your print provider’s requirements for the job; these references explain the underlying file and print settings.
Question or correction? Contact Ezra, Endorr Co-founder and Head of Digital Commerce, at ezra@endorr.com.
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