Heat Hierarchy: Transfers, Applied Vinyl and More
Entire multimillion-dollar revenue streams can be achieved from one type, let alone a combination, of heat printing technology.
By Josh Ellsworth, General Manager, Stahls' CAD-CUT® Direct™
Heat printing technology is diverse, developing and in demand.
While the function and form of the various types of technology that fall under the heat printing umbrella are diverse, when leveraged appropriately, entire multimillion-dollar revenue streams can be achieved from one type, let alone a combination, of heat printing technology.
Screen Printed Transfers
The closest relative to screen printing in the heat printing world is a screen printed transfer. The transfer presents several advantages over traditional screen printing, and can be leveraged depending on the business type, the occasion or even the location. To dive deeper, consider event printing. Screen printing on-site at an event would be a major undertaking. Today, screen printing is leveraged in on-site printing with a preprinted inventory of garments, by size, by color, etc. This is a risk not worth taking for some finance savvy entrepreneurs.
Imagine when the event gets rained out, or when customer after customer requests a large T-shirt, when the inventory that remains is just small sizes. While experienced, on-site retailers can make general assumptions on size, it is an unnecessary risk. Screen printed transfers allow a retailer to commit the design selection to size and color of garment upon order, or upon a much leaner replenishment of inventory. The risk and cost of a transfer is minimal compared to that of a decorated T-shirt.
Next, let's consider the standard left chest print job. With smaller graphics in high quantities, screen printed transfers can present substantial savings due to a concept called gang sheeting. A large quantity of cap-sized, left chest graphics are nested on a screen, and often 20-plus designs can be printed with a single stroke of the squeegee, reducing design cost substantially. Lastly, from a sheer start up investment cost, the heart of a heat printing business - the heat press - is much more affordable than screen printing equipment. Contracting the production of screen printed transfers to someone else and simply pressing them on will allow quality control in-house while limiting capital expenditures and, ultimately, space, clean up, etc.
Screen printed transfers do carry the same cost principals as screen printing, since screen printing is leveraged as the manufacturing vehicle. For instance, the number of colors drives cost, as does the quantity. At higher volumes, transfers become very affordable; consequently, stock transfers, such as the American flag, are often run in bulk and utilized in a pick and ship or pick and press strategy, carrying the burden of inventory of popular design elements. Consider this same principle in sourcing stock numbering of popular fonts. A screen printed number can be a very affordable way to decorate athletic fabrics, assuming the ink is properly formulated.
To this end, screen printed transfers are available in a wide variety of ink formulations with performance factors ranging from fabric compatibility, adhesive melting point, stretch, dye inhibiting, foil receptivity and more. Pretty much, anything that would be considered for a screen printed ink application can be considered in screen printed transfers. For instance, four-color process transfers present advantages for full-color images and applications.
The next logical progression from screen printed transfers is a transfer of another type. Let's call them digital transfers. Digital transfers come in a variety of styles due to the digital printing technology types capable of producing heat printed graphics. The term, digital transfers, encompasses those that are printed with aqueous inks, solvent inks, laser toners, sublimation inks and other up and coming, but less developed, technologies such as latex and sepiax ink.
Entire articles are written on each technology within this digital transfer grouping as each has its benefits, value and experts "betting" on each being the big breakthrough to solve the demand of short-run, full-color custom graphics. In my opinion, the best approach in today's market is a combination of digital technology sets, depending on your business model. Let's explore the pros and cons of each.
Aqueous Ink Digital Transfers
There are a wide variety of transfer papers in sheets and rolls that can be printed with an aqueous ink printer. These printers are primarily those purchased off the shelf at an office supply store as a home-based printer. Aqueous printed digital transfers are very popular due to the sheer number of users operating this printer type due to its low cost of entry. The transfer papers are available in two basic styles with variations of each: A clear and an opaque. The clear is reverse-printed and intended for light-colored, primarily white, garments. The opaque is a two-layer paper with a white transfer media affixed to a carrier paper. The opaque is ideal for darker-colored fabrics. In either case, the printed transfer requires a trimming process to remove the "heat printing box" inherent with any aqueous inkjet printed technology. The trimming can happen by hand with scissors for basic shapes, or can be expedited with the investment into an optical eye cutter that can read printed registration marks for precise trimming. At this point, the excess material needs to be removed via a weeding process and, in the case of opaque transfers, a heat transfer mask needs to be applied for maintaining the spacing and placement of the design on to the garment. At the end of the process, the wash durability is only about 10 to 15 cycles. Due to the time consuming production process and the limited durability results, aqueous ink digital transfers are typically leveraged by smaller shops just getting started in heat printing, and are not advisable for high-quality, high-durability results.
Solvent Ink Digital Transfers
Solvent ink digital transfers are the advanced version of aqueous transfers. The solvent or eco-solvent ink actually penetrates the surface of the heat transfer media being printed, and results in a highly durable, high-quality transfer. Solvent printers are common among sign makers and, with the advent of solvent printed transfers, printer manufacturers are now making smaller format solvent printers specifically for apparel decorating. The process and choices are very similar to the former technology with two core printable film types: Clear and opaque. While several varieties exist in each type, the foundation is that clear media is ideal for light colors as opaque is for darks.
The workflow for clear: Reverse print, cut, weed and heat apply
The workflow for opaque: Positive print, cut, weed, mask, heat apply
Due to its popularity for durable heat transfers, much innovation exists in media types to cater to different fabric applications such as high stretch media, dye migration blocking, metallic printable, reflective, low temperature adhesion and more. The media is typically sold in rolls, ranging as wide as 60 inches for large-format, heat applied applications.
Laser Toner Digital Transfers
Laser toner digital transfers are a technology set unto themselves, but the CMYK+White toners yield full color results which place them into the digital transfer category for our purposes. As the name suggests, transfers are printed on transfer paper through laser printer and laser copier devices. Once again, the fundamental paper styles are either clear or opaque, with a new category of "weeding free" paper arriving a couple years ago. Much development and innovation is still happening in this category, as laser printer manufacturers incorporate the use of white toner for decorating dark fabrics with clear paper. The new paper technology also allows for transferring only where the image is printed, rather than requiring trimming or transferring the entire paper square.
Sublimation Ink Digital Transfers
Such transfers are also very unique. The concept is all chemistry; sublimation ink is printed onto sublimation paper in a mirror image. The transfer is then heat printed onto any compatible fabric, and the ink actually releases from the paper, effectively dyeing the fabric itself, resulting in a highly durable design. The trick with sublimation is the fabric. It must contain a high percentage of polyester, and must be white or very light in color. Sublimation is leveraged extensively in the sports fabrics market since polyesters reign supreme. It is also leveraged by cut and sew operations to dye complete fabric panels via rotary drum heat printing prior to garment fabrication. Sublimation is also routinely used on polymer-coated ceramics, plastics and metals for awards, gifts and recognition. All in all, it is a very durable, high-quality heat printing technology.
The next category of heat printing technology is that of cut film transfers. Cut film transfers are created by utilizing a vinyl cutter of some sort, and a roll or sheet of heat transfer film. Cutting technologies capable of cutting heat transfer film include water jet, laser and knife cutting equipment. The workflow is very simple: Cut in a mirror image, weed and heat print. The advantage of heat transfer film as opposed to the aforementioned digital technology and screen printed transfer sets is multifaceted. First and foremost is the workflow and cost savings for low quantity single color designs. Heat transfer films come in a wide selection of colors, and are already laminated to a PET carrier. The films then can be cut, weeded and applied. All spacing integrity is maintained and no additional step of masking is necessary.
When compared to screen printed transfers or screen printing in an identical design, there will always be a breaking point where it makes more sense financially to pick one over the other. This is typically around 24 to 36 pieces of an identical run, with heat transfer film presenting significant advantages on any one-off variable data. The next reason a shop would leverage heat transfer films over digital printing technology sets is the breadth of effects. Full glitter, foil, reflective, puff, flock and neon finishes present solutions not available in many of the digital printing technologies discussed. Heat transfer films are also highly durable, high quality and feature advanced adhesives allowing application onto almost any fabric. They are leveraged extensively for name and number solutions, the most cost effective way being to source numbers prefabricated and ready to apply, and joining them with a custom cut name at the heat press for application of a player combo.
Heat printing is largely based on the heat activated adhesives' ability to stick and stay on fabrics, and the fact is that these adhesives can be a bonding agent between not only plastisol inks, polyurethanes and fabrics, but also in joining two fabrics together. There are a variety of fabric transfers created with heat activated adhesive and other varying effects. The most popular fabric type is polyester twill. This twill is laminated with adhesive and cut with a cutting device for permanent heat application. Typically, laser cutting is the preferred technology due to its ability to seal the edge of the twill and prevent fraying in laundering cycles. Heat transfer twill is often finished with either a straight edge or a variety of proprietary techniques including a simulated stitch replicating that of sewn appliqué. Recent developments in fabric transfers also incorporate digital printing onto fabric for full color twill transfers for a patch-like application. Also, with the demand of modern, softer styles, distressed looks from softer, cotton fabrics are being manufactured and sold as fabric transfers.
Jewel-like transfers are still growing in popularity. Rhinestones headline the category and can be manufactured in a variety of ways. The do-it-yourself workflow for a small shop is done by creating a template with a cutting or engraving machine and brushing the stones into the template, then masking, while larger shops are leveraging automated equipment that robotically picks and places stones onto a sticky transfer sheet for heat application. Stones can encompass an entire design in multiple sizes and colors, or can be utilized as accents to most of the technology already discussed. In addition to rhinestones, spangles are making a splash recently. These thread-free heat printed sequins are created using robotic technology similar to the rhinestone machine. Some businesses have the market to invest in the equipment while most contract the work out to a transfer manufacturing house. The finish is unique and hologram-like, possible in many shapes and styles that offer a lighter weight solution to stones or traditional sequins for wearable applications.
The world of heat printing is more than what some used to call "iron-on." It's a deep category with many technology sets and unique applications for businesses of all types. Whether you are starting up as a new store or looking for a way to diversify into the next big revenue stream, heat printing is lean technology that can facilitate profitable growth.
Josh Ellsworth is general manager of Stahls' ID Direct. He has been in the industry for 10 years and within that time has helped to implement apparel customization solutions in some of the largest manufacturers in the United States. Josh speaks regularly at industry trade shows and continues his educational efforts online through his website joshellsworth.com.
This article appeared in the SGIA Journal, Fall 2013 Issue and is reprinted with permission. Copyright 2013 Specialty Graphic Imaging Association (www.sgia.org). All Rights Reserved.