How to Supply Artwork for Custom T-Shirt Screen Printing
Custom T-shirt Screen Printing involves a number of steps, all of which are essential to a high quality printed t-shirt. The first step is obviously preparing the artwork, then followed by screen coating, stencil/film printing, exposure of the emulsion on the coated screen, washing out and finally printing. Washing up the screens and emulsion removal for screen reuse are the final steps in the screen printing cycle. If any of these processes fail the final product will be sub-optimal.
1. Vector artwork. If possible supply the artwork in vector form (eps, ai, pdf, or cdr). The benefits are that file sizes are minimised and our rip (raster image processor) outputs a sharper film/stencil compared the same design submitted in raster form (jpg, png, gif). The reason being that if you rasterise the artwork in photoshop, our rip will rasterise the artwork again while printing. 2 levels of degradation. If you supply vector artwork, only 1 level of degradation occurs when the rip rasterises the artwork for t-shirt printing.
Besides producing a sharper stencil, vector artwork is much easier to separate than raster artwork for screen printing. If the design consists of multiple colours the screen printer has to make a separate screen for each colour. Vector artwork makes this step a breeze. If the artwork is a flattened png file, more time is required.
2. Use Black K=100 and not rich black if supplying separated artwork. We have calibrated our rip and film output printer to produce best results with K=100. There are many variations of rich black and some other screen printers may prefer a variation of rich black for film output but with us we need K=100 for best results. What black you need depends on the rip the screen printer is using. With K=100 our system lays down enough black ink to block ultraviolet light and just enough so that the black ink does not bleed into unwanted areas (also known as dot gain).
3. Outline text and have raster elements at 300 dpi. Remember to outline the text in case we do not have the font you have used installed and to keep the file sizes smaller. 300 dpi seems to be the sweet spot for film output for screen printing. Any higher and the resolution will not hold. Any lower and unwanted pixelisation may occur in the screen printed t-shirt.
4. Contrast. Have a lot of contrast in your design. It is very difficult to print fine gradients with the t-shirt screen printing process. You will not see a difference if your colours are C=100 and C=95 but you will if its C=100 v C=80. Screen printing is a mechanical process which is not very precise so we need a lot more leeway compared to offset or digital printing.
5. Other considerations. Provide a mock up if you have an unusual position for your artwork. A picture is worth a thousand words. Supply PMS colours if you need an exact colour match for corporate logos.
If you follow these guidelines, your t-shirt printing job will proceed more smoothly.
How to Supply Artwork for Custom T-Shirt Sublimation Printing
Dye sublimation t-shirt printing is a digital process where ink is first printed onto sublimation transfer paper which is then heat pressed onto a synthetic garment under great pressure and heat. The dye sublimation ink vaporises and penetrates into synthetic garment (usually polyester). Upon cooling the dye particles are trapped in the garment which results in a colourful printed product of great durability and soft hand - you cannot feel the ink.
1. Use CMYK colour space. Sublimation t-shirt printing is a digital process and most commercial sublimation t-shirt printers, including ours, utilise only 4 colours in the ink set, namely CMYK (cyan, magenta, yellow and black) so only submit artwork in the cmyk colour space if you want the final result to approximate what you see on your monitor.
If you send Adobe RGB artwork, we can still print it, but the colours will vary if the colours you have used are out of gamut. The Abobe RGB colour space has much more colours than the CMYK colour space.
2. Keep Raster artwork between 150dpi and 300dpi. Any higher will just increase file size and not result in a higher quality print on the t-shirt. During the transferring process, the ink vaporises and condenses back. This disperses the dots printed so we do not require any higher resolution. Even 72 dpi is sufficient for most jobs provided the artwork is sharp.
3. Keep text in vector form outlined. This will result in a sharper print for small text and keep file sizes smaller. Rasterising text will just degrade the final result, plus rasterising also increases the file size. Remember to outline the fonts in Illustrator or curves in Corel.
4. Other considerations. Provide a mock up if you have an unusual position for your artwork. A picture is worth a thousand words. Please note that the colours printed onto the t-shirt will be close but not exact. We do not provide a PMS colour matching guarantee for sublimated printed t-shirts. The colour will vary according to the garment material, the pressure of the heat press and the temperature of the heat press. There are simply too many variables to account for. Of course if it is a large project, we can print samples for inspection and colour proofing. We need to print swatches with various colour mixes for the customer to choose from. For a one off t-shirt it is not economically feasible.
Submitting Hand Drawn Artwork
We can print t-shirts from hand drawn artwork. If you plan to make a single colour print eg red print, you still need to draw your artwork in black onto white paper. Use a dark black pigment pen to colour in all the places where you wish to have the design printed. White smooth paper is best. We need to scan in the artwork, convert the design to black and white and print out a positive film for exposing our screens. Black sketches on white smooth paper allows us to convert the artwork easier and details are sharper.
You can also submit full colour hand drawn artwork if you wish to print onto a white t-shirt. We cannot print full colour artwork onto black or coloured garments.