ImagesMagUK_May_2021 MAY 2021 images 31 TIPS & TECHNIQUES decisions. A modest white ink coverage can ensure a high margin on T-shirts for one-off events or applications that do not demand high quality. White layer generation As you need to print the white layer before the CMYK, the way you generate this layer will affect your costs and final quality. Sometimes it is easy to think that using full background coverage under CMYK will offer the best results, but it is not entirely true. If your image is based on dark colours it isn’t always necessary to use a lot of white under the CMYK. If your image is composed of light colours, then you need to increase the coverage in the white layer, but you may not need a full background. When printing a white image or white text, you may need to use the full background mode, using white ink as a spot colour with 100% density. If this particular approach doesn’t achieve a good white result, you may need to overprint the white image. You can generate a white layer with the same amount of white ink under the CMYK, or in greyscale mode, which prints less white ink under dark colours and more under the lighter colours. With this mode, you can achieve better quality results with reduced fabric stiffening in a faster time and with significantly less white ink consumption. To increase white ink density, you can use a bigger dot size and/or overprint the white area. Many printers working at high resolution use narrower passes, letting the white ink settle better and offering better coverage and more uniform ink density. You should use overprint and high resolution when white areas are visible, and you want high density. However, it’s important to consider that this also increases the production time and reduces the number of T-shirts you can print. In summary Appropriate white layer generation can reduce the white ink consumption between 30-70% and can reduce production cost by 20-30%. Using too much white can negatively affect the results and increase production costs. Printing at a higher resolution or with several passes gives the best quality, but can significantly reduce productivity. It’s important to identify the right settings for white and CMYK layers. Some RIPs also include the capability to consider the T-shirt colour when calculating the final colour output, reducing the ink consumption. Achieving the desired quality at a lower cost is key to improving your profit. It’s also vital to follow recommended maintenance to reduce cost and downtime. The white dots indicate that there is too much white under the CMYK layer