User login

Special FX with H2O

(March 2003) posted on Mon Aug 25, 2003

Learn how to print these inks through garments to produce images with a totally unique appearance.


By Rick Davis

Working with different companies and in different countries allows me to discover applications in which printers have set aside traditional printing techniques in favor of thinking outside of the box. As a result, these textile screen printers have produced never-before-seen effects. In this column, I will highlight one such application that uses water-based ink to produce a special-effect garment with an all-over decoration. Production issues In previous columns, I have discussed the practice of printing a graphic on the inside of a garment in order to produce an aged or worn graphic effect on the outside of the garment. That particular printing technique works well in producing the desired effect, but the drawback of having plastisol on the inside of the garment is that the ink film can be abrasive and irritate the skin unless its printed very thin through high-mesh-count screens. In the special-effect application discussed here, I will explain how to print on the inside of a garment with water-based ink to produce a different effect over the entire garment and avoid the heavy hand of plastisol. Over the years, as plastisol-ink technology progressed, the printers that continued to work primarily with water-based inks fell behind by not immediately taking advantage of the relative ease of working with plastisol inks. These days, finding a domestic textile shop that works with water-based inks is like finding a four-leaf clover, and if you do locate one, you're lucky! Few printers want to bother with water-based inks because these inks tend to dry in screens. Additionally, the applications in which they can be used are more limited, as is their ability to support special effects. They also require a different approach in curing. But on the other side of the coin are the benefits that water-based inks have to offer. These include a very low cost as compared to plastisols, the softest hand possible on a garment, and the fact that there are now some special-effect applications that can only be achieved through the use of water-based inks. The application This application uses water-based inks to convert a regular, white, 100%-cotton T-shirt into a garment with a two-toned heather effect. Before you start, you need to understand that the shirts are made using a cut-and-sewn construction and you will be printing the individual panels before they are sewn into complete garments. The printing itself can be as simple as all-over (100%) coverage of the front, back, and sleeve pieces, or as complicated as you would like to make it. The garment panels are printed so that the ink is applied to what would be the inside of the fabric. As the water-based ink is pressed into the fabric, the inside--or in this case, the print side of the fabric--will receive all-over coverage with whatever image you choose. When the panel is turned over after the ink has been dried, the water-based inks will have penetrated the material and will be visible on the outside surface of the fabric as faded, heather-effect images in the original printed color. The degree of ink penetration you achieve with this process will depend on a number of factors, including the knit density of the fabric, the viscosity of the water-based ink, and squeegee speed and pressure you use. When the print is cured, the inside of the fabric will portray a completely accurate representation of the image, while the outside has a faded-looking version of the graphic. When worn, the completed garment will fool the viewer into thinking the shirt is inside out when it is not. 20 You can use this technique with virtually any image and apply the image to any area of the garment you desire (front, back, etc.). It can be a simple, single-color image or a design printed in multiple colors. Another variation to consider is printing an image with regular plastisol or special-effect ink on the outside of the fabric after the water-based print is cured. The interplay between the faded water-based image elements and bold plastisol or special-effect graphics can lead to some interesting results. You can also wait to add other effects after the garment has been sewn, but keep in mind that this may be less cost effective. Another aspect of this technique to consider is that no two garments will be exactly the same. Printers who have already attempted this technique have tried to achieve a consistent look from garment to garment. But the appearance of the finished prints will vary in hue and intensity based on the ink color and how much the ink penetrates the fabric, which is difficult to control. Special concerns I recommend extensive testing to determine what your finished results will be before you go into production using this process. As I previously mentioned, the knit of the fabric will play a great role here. Heavier knit garments will limit the degree of penetration of ink into the fabric and will restrict the intensity of color show-through. Lighter knit fabrics will cause the opposite to happen by allowing more ink to penetrate the fibers of the garment so that the degree of color to show through is much higher. In the latter situation, you can prevent total saturation of the garment by adjusting the squeegee pressure and speed. Another aspect to keep in mind is to maintain the cut-piece format. Although you can attempt this technique with a sewn garment, you will experience a natural buildup of ink along the seams, collars, and cuffs, which will take away from the overall effect. The additional buildup of ink along these areas of the garment will also add to the complications associated with properly curing thicker ink deposits. Speaking of proper cure, make sure that the water-based ink used in this application is thoroughly cured. Curing water-based inks properly requires exposure to heated forced air in order to drive the water out of the ink and fabric. Although this seems like an awfully basic point to address, I still come across a number of facilities that run water-based inks through radiant-heat curing systems. While it is possible to cure water-based inks with radiant-heat dryers--providing they're long enough--I wouldn't recommend trying this technique without using a high-velocity, forced-air dryer. Ensuring a proper cure also means checking your dryer temperature regularly. Finally, always conduct a wash test on cured samples to confirm that the ink is properly set. Take the plunge Many textile screen printers see water-based inks as too troublesome to work with and too limited in their usefulness. But as this print-through application demonstrates, water-based inks can open new opportunities for your business with minimal adjustments to your production procedures.


Terms:

Did you enjoy this article? Click here to subscribe to the magazine.