Garment
More than a preview: with halftone set to Auto the garment decides which tones carry ink — light areas on a dark shirt, dark areas on a light one.
Knockout
One click: finds the background from the edges of the artwork and takes it out. Everything below tunes that.
How far a pixel may differ from that colour and still be removed. Raise it for photos and JPEG artefacts, keep it low for clean vector art.
Garment knockout
Drops any part of the design that already matches the garment colour, so the shirt shows through instead of the press printing over it. Saves ink, and avoids a slightly-wrong patch of colour sitting on the fabric. The colour comes from the Garment panel.
Mask edge
A part-transparent pixel tells the RIP that some colour is present, so it lays white underbase there and the print comes back with a haze around every edge. This forces the alpha channel to all-or-nothing. Leave it on unless your RIP handles a real alpha channel.
Where the all-or-nothing decision falls. Lower keeps more of a soft edge, higher trims it back.
An anti-aliased edge pixel is part artwork and part old background. Keeping it leaves a pale rim around dark art; trimming a pixel or two removes that ring outright. Invisible on the garment, unlike the fringe.
Levels
Same three steps as the Photoshop dialog, in the same order: clip to the input points, apply gamma, then rescale into the output range. Drag the markers or type the numbers.
Halftone screen
The screen reads the tones after Levels, so set the levels first — that is the order the press sees.
White underbase
A separate white layer the size of the artwork, pulled in from the edge so it does not peek out from under the colour pass. DTG on dark garments prints this first.
How opaque a pixel must be before the underbase covers it.
Print size & resolution
Printer setup
What the exported PDF actually contains. A PDF stores no DPI — it stores an image drawn into a box measured in points, and a point is exactly 1/72 inch. Every figure below is that geometry.
Export
Exports re-run every adjustment at full resolution, so what you see while dragging is a fast preview and what you download is not. The PNG carries its resolution in a pHYs chunk; the PDF is built on the server so the artwork keeps a real alpha channel.
Print it on a garment
Send the finished design straight to a shirt in the shop. It goes into your cart at the print size set above, with the artwork attached for production.
The personalizer knows how wide each area really is, so the studio sets the print size from it. Uncheck to keep the size you set above.