From t-shirt jersey fabrics composed of blended fibre types, to performance sportswear, fleeces and treated fabrics – the selection is huge. This myriad of choice for consumers does, however, come with plenty of challenges for the screen-printing process and for ensuring that you get the best results from your MagnaPrint water-based inks.
In this blog post, we’ve put together some useful tips and tricks to help you overcome some of the more challenging issues that certain fabrics may cause in the screen-printing process.
Dye Migration
Ever suffered with colour from your fabrics bleeding into your prints? Dye migration is a common problem that occurs with polyester garments and is caused by dyestuffs from the polyester fibres transferring into the ink on your screen-printed garment.
Heat plays a key role in dye migration, so the ‘bleeding’ usually starts to appear during the curing process or when the fabric is washed. Fortunately, there’s an easy fix to eliminate this problem when printing on polyester or blended garments.
MagnaPrint® Migration Blocker Black is a highly effective under-base ink that prevents colour from problem fabrics bleeding into your design. It helps to build strong opacity and preserves the brilliance and detail of overprinted whites and colours.
The above images illustrate a design where the tiger area has been printed over a blocker and the snake area has not. We can see how the polyester dye has bled into the white print on the snake, whereas the tiger has remained bright white.
Garment Shrinkage
Perhaps you’re printing on something particularly stretchy like polyester leggings or performance wear and shrinkage is giving you a headache with print registration. Garment shrinkage can occur during flash curing, which in-turn can cause a perfectly registered print job to suddenly move off registration. You can experiment with reducing your flash temperatures to find the optimum for that particular fabric.
At Magna, our print technicians experienced this issue when working on print trials for some sportswear jerseys. After marking a pre-measured grid on the garments, they found that the garment had shrunk by 10mm in both length and width after going down the dryer. If faced with an issue like this, you can pre-shrink your garment using the dryer before printing to avoid any movement during the printing process!
Fabrics “Sweating”
If you start to experience excess moisture entering your printing process, often from the garment itself or its application to your pallets, certain fabrics can begin to “sweat” when you apply heat to them. This is especially true of large print surface areas and can cause the garment to move around your pallet or platen, a phenomenon that is typically worse with polyesters, fleeces, and wool materials.
A key to keeping on top of this is ensuring that you regularly clean excess lint and glue off your pallets. We also recommending not diluting MagnaPrint Pallet Adhesive ST, as the excess moisture can cause sweating once your pallets get hot.
Puckering & Pin-holing
If you’re working with a particular tricky garment, you could be faced with puckering and pin-holing. Pinholes are small imperfections or quite literally holes that can appear in your prints. They can often occur from mesh contamination or screen defects; however, certain problem fabrics can also cause the issue.
Depending on the fabrics’ fibre composition, using an underbase like Migration Blocker Black or MagnaPrint Killer Base, helps to matt down the fibres, providing the perfect surface for overprinting – especially if you’re printing something particularly fibrous or coarse.
If you’re a manual printer, our high solids water-based range MagnaPrint Self Levelling was developed specifically to reduce issues with pin-holing occurring when building up multiple layers of ink and can help with achieving optimum ink coverage.
Learn more
The examples in this article are just some of the challenges that can screen printers can be faced with when printing on certain garments and fabric types. Outside of this there are plenty more considerations you can make so stay tuned for more tips and tricks from our team. You can also learn more about printing with MagnaPrint water-based inks by accessing our Technical Hub.
