Industry expert Tony Palmer explains how to get the best results when decorating stretchy technical fabrics

Fitness and athleisure apparel is one of the fastest growing sectors in our industry. These performancewear styles are usually manufactured in highly-technical fabrics, which are specially designed to stretch to up to twice their original size and, in some cases, also repel water. While this is a fantastic result for those of us still sticking to last year’s resolution to go to the gym (and not just join it), it can make life complicated for garment decorators. However, by following a few simple rules you can grab a piece of the (low-carb) fitness and athleisure apparel pie.

Ink Selection

The main factors to consider are the basic properties of the fabric and the ink.

Plastisol ink  This has good opacity, which is essential in gymwear, and has a variety of additives which can help with any issues:

• Stretch additive can add extra durability to cured ink and give good stretchability to a print but, as with all additives, the more you add to an ink the more the opacity is reduced, so a careful balance is required.

• Low Cure Additive will reduce the curing temperature of the ink. The idea of this additive is to bring the curing temperature closer to the acceptable temperature of the fabric. Some high-performance fabrics shrink and crinkle under high temperatures and most polyester dyes will start to migrate above 140°C, so reducing the amount of heat needed to achieve the final cure does have some advantages.

Low-bleed ink This is usually supplied ready to use and is manufactured to have dye-blocking properties and lower curing temperatures – an essential tool when dealing with man-made fibres and heat-sensitive products. The thing to watch for is the balance between printability, cost and opacity.

Water-based ink The options are rapidly evolving, and new breeds of performance water-based ink are emerging daily. The new range of high-solid inks have excellent adhesion to today’s polyester-based fabrics and are the ink of choice for the main high street sportswear manufacturers, due to the excellent fibre matt-down and soft feel. Water-based inks lack the low-bleed attributes of plastisol, but this can be remedied with a separate dye blocker, usually applied via a separate screen using a special ink, which typically has carbon-blocking elements.

Silicone ink This has all the attributes you’re looking for when using technical fabrics: ultimate adhesion properties, the best stretch that can be found in any ink system, high dye blocking capability and low curing temperatures. The only downside to these inks is the lack of wet-on-wet printability and the high solvent content necessary in clean up.

The Full Length Legging from Kustom Kit

Heat transfer vinyl This alternative can give great results in single colours. The process involves cad-cutting a thin film of material and applying it to the garment using a heat press. New materials are now available that allow you to apply the film at temperatures as low as 120°C and with as little as five seconds press time. This kind of decoration is perfect for branding as it gives high detail on polyester fabrics. Choosing the correct material is vital as many types are available. Check that the vinyl you choose will adhere to polyester at low temperatures.

Process

Printing onto new sportswear isn’t as scary as most people presume. However, there are some basic principles to keep in mind:

Stretching  New fabrics have a fantastic ability to stretch over the bits of our bodies which are the reason we’re going to the gym in the first place. However, you must pay attention to this when handling this material: if you stretch a piece of fabric onto the press and then apply the first part of a decoration, for example an underbase, and then dutifully add heat to gel the first layer, the inevitable is going to happen – the fabric loosens from the glue and returns to its former shape, resulting in ruined prints.

If you apply enough industrial strength double sided tape (we’ve all done it) to the platen to avoid this, the fabric stays on the board all the way through the process. But, as you remove your perfect print and admire how you have defeated the forces of nature with PVA glue and carpet tape, you realise that the A4 sized print you started off with is now the size of a perfect little business card! Removing the fabric without care can also be the most efficient way to convert a soccer ball to a rugby ball in one pull away from the glue.

Heat Management  I’ve covered this topic before, but remember that printing is all about heat management. New fabrics are primarily man-made and use dyes that are very sensitive to heat. Inks of all types can be the perfect conduit for a heat-awakened dye to run along and play peek-a-boo when the customer opens the carton the next day. Use lower temperatures to cure and always get rid of the latent heat building up at the end of the process, whether you’re using a dryer or press. You must kill the heat as quickly as possible to stop the dye migration process.

Always read the label

Gymwear is here to stay. As we approach the time of year where we all start making promises to ourselves about using our gym membership – and begin shopping for the latest stretchy fabrics to enable us to at least look like we mean business – it’s the perfect time to look for business decorating these new high-value products. But, before you start, understand the properties and limitations of the material you’re decorating; read the label and understand what ink will adhere best to the primary ingredient in the garment. Provided you manage the heat and take care in the handling, fitness and athleisure apparel will soon become an easy addition to your decoration portfolio.

Tony Palmer has been in the garment decoration industry for over 30 years and is now an independent print consultant working closely with print shops to get the most from existing processes and techniques. Tony is passionate about keeping and enhancing production skill levels within in the industry. He is the owner and consultant at Palmprint Consultants, offering practical help and assistance to garment decorators all over the globe.

www.palmprintuk.com