Davis reflects on foil effects and explains how to use foil transfers to make your decorated garments shine.
By Rick Davis
As today's leading garment-printing companies work to come up with innovative decorating techniques and materials to set their products apart from the competition's, many find themselves revisiting special-effect products and processes from years gone by. One of the applications that is being resurrected with increasing frequency from the special-effect archives is foil-transfer decoration. Foil garment-decorating materials have been around almost as long as the heat-transfer application process itself. And may garment shops are finding foils effective for adding pizzazz and diversity to their current product lines. The high reflectivity of foil transfers makes them a valuable asset for any printer wanting to create eye-catching graphic effects. They also make an interesting alternative for applications in which reflective inks might be considered. Cost considerations Foils can certainly add value to a garment, but they also add time and cost to the production process. As we all know, in today's competitive marketplace, garments must be handled as few times as possible during the decoration process in order to maintain production efficiency and keep costs to a minimum. The downside to foils is that they require additional steps to apply them to a garment after it has been printed, introducing both additional labor and extra material costs. Their use may also necessitate the purchase of heat-transfer equipment if a company doesn't already have it. The greatest amount of added cost lies in the handling of garments during the transfer process. The actual transfer time will vary depending on the specific application and effect you are attempting to achieve. The upside to foils is that they are actually very inexpensive in comparison to other special-effect material, such as reflective and high-density printing inks. The actual cost of the foil itself is, of course, dependent on the amount of foil required to produce a given image. The cost per garment can range from as little as 0.2-10 cents/image based on the size of the foil-application area and the type of foil being applied. It is best to cost out your foil based on the overall image area, rather than just the percentage of the image area that will be covered by the foil. Some waste will be inevitable since the foil that remains on a sheet of foil-transfer material after it has been used once is likely to be of the wrong shape or size to be reused for another application. Foil selection The first step in foil-transfer decoration is to ensure that the correct type of foil will be applied to the garment. Dozens of different transferable foils are available on the market, and not all are compatible with textiles. This is something you'll definitely want to verify if you are contracting out the production to a secondary source, especially if it's overseas and doesn't have access to the same materials you do. Some foils will transfer and adhere to a plastisol ink or transfer adhesive and look great on the garment. But after the first wash, they disappear from the print. Always check with the manufacturer of the foil if you are not sure of the foil's compatibility with particular inks, adhesives, or garment materials. Foil adhesives The adhesive to which foils are applied vary. Some foil manufacturers offer adhesives specifically for their products. Others recommend applying their materials to conventional plastisol prints. To assure the best possible foil performance, find out what the foil manufacturer recommends. If the manufacturer says his product is designed for use over plastisol ink, test different plastisol brands to determine which give you the best results. Many printers today are very successful using high-density clear plastisols as adhesives. Fabric concerns Even if you use a foil that is designed for textile applications, this doesn't mean the foil will adhere to all materials. The range of fabrics on which foils will hold up well is rather limited. Fabrics with smoother, more tightly woven surfaces, such as T-shirts, sweatshirts, and denim, will work best. This is because the adhesive or ink film to which the foils will stick can be printed more evenly and consistently on these smooth materials, which means more surface area to which the foils can adhere. The other end of the spectrum includes materials like knitted sweaters or corduroy, which offer minimal fabric mass and an uneven surface on which it's difficult to form a smooth ink or adhesive film. Nevertheless, foil can be applied to uneven surfaces, as long as you understand that it will only produce small, broken image elements rather than continuous (solid) image areas. Depending on the fabric texture and the nature of the design, this can occasionally be a desirable effect, but you'll only know if you test the material. Applying foil Applying foil is a very simple process. First the adhesive or clear plastisol is printed onto the substrate, then it is dried as normal. After drying, the foil transfer paper is placed over the image and a heat-transfer press is used to apply the foil, generally at around 350°F or 175°C for 4-12 sec/image. As the heat press forces the foil into contact with the ink film, the ink film remelts and bonds with the foil. After the transfer cycle, the garment is removed from the heat press and allowed to cool slightly. Then the transfer carrier sheet is removed from the garment. The carrier should pull away from the ink film easily and smoothly, leaving foil only where contact was made with the ink. The transferred foil on the garment should be smooth with a mirror-like reflective surface. Occasionally when working with foils, you may experience small voids in the image area where the adhesive or ink film did not completely melt and smooth out during the transfer process, and the foil consequently didn't transfer completely. If this occurs when you are applying red foil to a red or similarly shaded garment, the effect may not be too noticeable. But if you apply a foil with a color in high contrast to that of the garment (e.g., red foil on a white shirt), the voids just scream. The solution to this problem is to tint the foil adhesive or clear plastisol so that its shade is similar to that of the foil. This way, any voids that occur will be masked by the adhesive. The mesh to use when applying the adhesive will vary depending on the substrate surface. Caution should be taken to ensure that you do not apply an excessive ink-film thickness, because the printed area may lose definition as the ink film remelts during the transfer process. Mesh counts typically range from 125-230 threads/in. depending on the fabric type. Another application option that can help you achieve a smooth finish is to actually print plastisol or adhesive directly onto the foil transfer sheet. After printing, gel the adhesive or ink as you would with any heat-transfer print. After the transfer is cool, apply the foil to the garment using the same procedures as noted previously for transferring to the printed garment. Note, however, that while this method works well for ensuring a smooth finish, it does add the complication of ensuring proper placement of the transfer on the garment. Enjoy the spoils of foils Foil performance depends on the foil and adhesive used, the type of fabric to which the foil is applied, and the method used to apply the foil. All foils will lose some of their reflectance due to tarnish over a number of washings, but overall, they should retain an appealing effect for a long period. Nevertheless, you should always pretest any and all foil, adhesive, and garment combinations, then wash test the finished garments to ensure that you will achieve durable and effective designs. With proper testing and care in production, foil can add value to your product line and your bottom line.
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