Margareta Fuchs and Everson Scheurich of DTG Merch explain why top quality DTG prints begin with top quality artwork, and advise on how to avoid the two most common mistakes when choosing graphics files

Everson Scheurich and Margareta Fuchs

Everson Scheurich and Margareta Fuchs 

It doesn’t matter if your DTG printer is running like clockwork, all your processes are optimised and the washfastness of your products is outstanding – if the quality of the image file you’re intending to print from is below par, the final printed result will also look below par.

Put simply, your prints will never appear better than the quality of the image/information contained in the original files.

There are numerous issues that design files can suffer from; here, we’ll discuss two of the most common mistakes.

Unwanted image elements

Unlike when printing on paper, DTG printing uses white ink. This has the benefit of allowing you to print on coloured and black textiles by applying an opaque white background (or underbase) over which the colour layer is printed. In DTG printing, the rule of ‘WYSIWYG’ (what you see is what you get) also applies. This means that every single pixel that contains image information – ie all areas that are not transparent – will be printed. This includes any white background pixels.

For example, let’s say you are asked to print a circular logo. The logo is supplied as a rectangular image file with a white background. As white is a printable colour, you’ll end up printing a white box around your circular logo design. The only time you do not need to worry about the white background is if you are printing with CMYK inks only. A white background is not the only image element you should watch out for: if your design has imperfections, they will also be printed. If the design is blurry, the print will look blurry. Or as the old adage goes: garbage in, garbage out. These aspects of DTG printing have some far-reaching implications for the way graphics must be created for print.

Tip number 1 Remove all elements that you do not want to see on the final result. When working with complex designs that have lots of detail, such as hair, this process can be complicated and time-consuming. Our advice is to either create the graphic correctly, without the extraneous details, from scratch or communicate the exact requirements to the designer so they can create the file accordingly.

Tip number 2 Pay extra attention when you choose the file format. When printing without the white ink, any file format supported by the printer or the RIP can be used. But if you’re using white ink, a file with transparent areas will be necessary. This requires the design to be saved in a file format that supports transparencies, eg PNG, PSD, TIFF. Take special care with JPEGs as this popular file format does not support transparencies. As soon as a JPEG file is saved, all transparent areas are automatically filled with white.

Tip number 3 Choose the right image size and resolution. The design size depends on the dimension of the print. For example, if a 30 x 30cm image is printed, we recommend an image size of 3,550 x 3,550 pixels. For a 40 x 50cm image, aim for approximately 4,750 x 5,900 pixels. We usually design our graphics as 4,700 x 5,900 pixel images or as vector files, which allows us to be prepared for all eventualities. Even though some printers can print at higher resolutions, we aim for 300dpi.The extra detail in a higher resolution image is often not visible once the image is printed on fabric.

Wrong colours

Colour differences between the original design on the screen and the printed result often cause unhappy customers.

Colour shifts are a well-known problem in DTG printing, for two reasons:
The colours on the screen are not representative of the printed result. Proofing is not possible, therefore designers have no information about which colours they can use and how they will look once printed.
Many printers ask their customers to deliver their files in the PNG format to reduce complexity and retain transparency, yet PNG files do not support CMYK.

Garbage in, garbage out – a 300dpi image resulted in the crisp print on the left, while a low-res image file resulted in the soft, poor quality print on the right

Garbage in, garbage out – a 300dpi image resulted in the crisp print on the left, while a low-res image file resulted in the soft, poor quality print on the right

It is important to be aware that the printer will always convert RGB files to CMYK using the printer’s profile for that specific product. The printer profile depends on factors such as the type of garment and its colour, the amount of ink used, the printing quality, and so on. As a result, a printer can use numerous profiles interchangeably, which can affect the appearance of the colours when they are printed.

However, it is not always the conversion from RGB to CMYK that causes subpar results. Unwanted deviations can occur in designs that were created for screen printing. In many cases, random colour values are used as ‘placeholders’ in the original file. When the file is used for screen printing, this is not a problem because the colour will be printed with a predefined and separately mixed colour. But when the same file is used in DTG printing, the colours that are embedded are not always the ones that give you the best results.

Remember, the printed image will never look better than the image contained on the image file. It is, therefore, imperative to take your time when selecting images for DTG printing and to make sure that your designers and customers are informed of the DTG’s specific artwork requirements.