DTF Halftone Workflow: Clean, Predictable Output
Use this order to avoid surprises: resize first, fix detail if needed, set levels, remove background, then halftone.
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1) Resize first (never after halftone)
Set final print dimensions before halftoning. Resizing later can create semi-transparent edge pixels and invalidate your dot structure.
Use px for exact digital sizing, or mm/cm/in with DPI when working from garment print specs.
- If you must resize after halftone, run Halftone and/or Solid Alpha again.
- Keep aspect ratio locked unless your output spec requires distortion.
2) Resolution Fixer only when needed
Use Resolution Fixer when source art is soft, compressed, or visibly pixelated. It improves edge definition before threshold-based operations.
- Detail: fine sharpness gain.
- Edge Sharpen: strength around high-contrast edges.
- Clarity: local contrast depth.
- Edge Smooth and Smooth Transitions: reduce harsh stair-stepping and gradient banding.
3) Levels to control where dots appear
Levels is the main gatekeeper before halftone. It controls what tonal range survives into dot generation.
- Input Black: pushes dark regions darker.
- Input White: pulls highlights darker/lighter based on movement.
- Gamma: shifts midtones without clipping extremes as fast.
- Output Black/White: compresses final tonal ceiling/floor.
4) Remove background and unwanted colors
Remove/Replace Color should happen before halftone so background cleanup does not break dot geometry.
- Use eyedropper target + tolerance to isolate near-background colors.
- Knockout mode removes to transparency; replace mode remaps toward a chosen color.
5) Halftone at the final output size
Halftone transforms transparency/intensity into printable dot patterns. Dial these values according to printer, film, and art style.
- DPI (dots per inch): image raster density. Typical print prep starts around 300 DPI.
- LPI (lines per inch): dot grid frequency. Lower LPI = larger/coarser dots; higher LPI = finer dots.
- Angle: screen rotation to reduce moire and improve visual texture.
- Min Dot %: minimum dot floor to keep tiny detail from disappearing.
- Solid Threshold: alpha above this stays solid, not halftoned.
- Edge Only %: limits dots to gradient-heavy cells and reduces noise in mostly solid zones.
FAQ
What is the practical difference between DPI and LPI?
DPI is image pixel density; LPI is halftone grid frequency. DPI controls available detail resolution, while LPI controls dot spacing/size. You typically set DPI first, then tune LPI for print behavior and look.
Why does my print look different when I changed size late?
Resampling after halftone alters alpha geometry and introduces interpolation artifacts. Always lock size before halftone to keep dot behavior predictable.