Turn soft fades and photos into clean dots on a transparent background, so the shirt shows through. Set it up for white shirts or black ones.
Open the editor with this effect
A DTF transfer is a layer of ink and glue. Big solid areas feel like a plastic patch, and a soft fade is a gamble, because the printer has to decide what to do with every half see through pixel in your PNG. Halftone takes that guess away. Every fade becomes dots that are either fully there or not there at all, so it prints the way you saw it, the transfer feels lighter, and the shirt colour does part of the work.
DTF prints white ink under the colour and then bonds it with adhesive powder. A pixel at 40 percent opacity has no clean answer. Some RIPs print it solid, some drop it, some print a thin layer that looks fine on day one and cracks after a few washes.
A halftone gives the printer only two states: ink or no ink. A shadow is bigger dots, a highlight is smaller dots, and the shirt fills in the gaps. That is also less film on the garment, which means a softer feel, better breathing and less white ink used.
It also gives the print a look. A coarse round dot reads as vintage, a fine one reads as a smooth photo, and a line screen reads as an engraving.
On a white or light shirt, the dots are the dark parts of the image and the shirt is the highlight. Big dots in the shadows, small ones in the light areas.
On a black or dark shirt, flip it. The shirt becomes your shadows, so you print the light parts of the image as light dots. In Bitgrain, set the Page colour to black and a mono halftone switches to light dots on its own, with the biggest dots where the photo is brightest.
For a coloured shirt, pick a custom Page colour close to the fabric. It lets you judge the result against the real colour, and it matters for the transparent export below.
Most DTF halftones sit somewhere between 25 and 45 lines per inch. Coarser looks more graphic and is very forgiving. Finer looks smoother but leaves tiny dots in the highlights.
Tiny dots are the main failure. A dot needs enough area for the powder to grab and hold through washing. As a rough floor, keep the smallest printed dots around half a millimetre across, which is about 6 pixels at 300 DPI. Anything much smaller tends to flake off or never transfer.
To clear out the tiny ones, raise Contrast in the halftone panel so the lightest tones drop to nothing instead of turning into specks, and check the result at 100 percent zoom. On a big back print you can afford a coarser screen, since nobody reads it from up close.
Lines per inch is how many rows of dots fit in one inch of the printed transfer. In Bitgrain the Dot size readout shows the spacing between dots in pixels of your image, so the maths is simple: divide the image width in pixels by the print width in inches, then divide that by the lines per inch you want.
For example, a 3000 pixel wide design printed 10 inches wide is 300 pixels per inch. At 35 lines per inch the dots should sit about 8 or 9 pixels apart.
Bitgrain fits up to 600 rows of dots across the long edge of the image, which covers every sensible DTF screen on a normal chest or back print.
DTF has no screen mesh, so there is no weave for the dots to clash with. The classic 45 degrees is a safe default and hides the grid best. 20 or 25 degrees works too if you want to match a screen printed piece.
Round dots are the safest choice for DTF because they have no thin corners to break off. Square and diamond dots look more graphic, and the line screen gives an engraved look. Ellipse dots chain together in the midtones for smoother fades.
Transparent background removes every pixel that matches the Page colour. The soft edge pixels around each dot are a blend of ink and page, and those stay in the file. That is why the Page colour should match the shirt: any edge pixel then blends toward the fabric and disappears on the garment instead of leaving a light halo.
For the crispest edges, open Advanced in the halftone panel and push Sharpness to 100. The dots become hard edged with almost no blended pixels at all.
Size the file in pixels for the print: inches times 300. A 12 inch wide print wants about 3600 pixels across, so start from a photo or artwork at least that big. The PNG does not carry a DPI setting, so set the print size in inches in your gang sheet or RIP software, which is where DPI is applied.
Open the editor from this page. A mono halftone is already applied to the sample, so drop in your own design or photo.
In the halftone panel, set Style to Mono and move Dot size until the spacing matches the lines per inch you want. Under Advanced, keep Angle at 45, Shape at Round and Sharpness at 100.
In the Colour tab, set the Page colour to your shirt colour. Check the highlights at 100 percent and raise Contrast if you see specks.
Export a PNG with Transparent background on and place it on your gang sheet. If you want to see it on a real garment first, drop it into Drapeshot, the Bitgrain mockup tool, pick the Original look so your dots stay exactly as they are, and download a mockup.
Somewhere between 25 and 45 suits most shirts. Go coarser for a vintage look or a large print, finer for a smooth photo on a small print. Whatever you choose, make sure the smallest highlight dots are not much under half a millimetre, or they may not stick.
Set the Page colour to black. The mono halftone switches to light dots, with the shirt standing in for the shadows. Export a PNG with Transparent background on and the black drops out, leaving only the light dots to print.
Yes. The Colour style keeps each dot in the colour of the image underneath it, and the CMYK style splits the image into four overlapping screens like a magazine. Both export as a transparent PNG the same way.
You can use every control for free and export a clean file to check the look, with a 1080 pixel limit. Pro exports at full resolution, which is what a real print file needs.
No. It is a classical halftone screen worked out from the brightness of your image, the same idea a print shop RIP uses. It runs on your device and nothing is uploaded.