Printing Dark T-Shirt Transfers with OKI White Laser Printers

Dark T-Shirt Transfers with White Toner Laser Printers

The OKI PRO 920WT and 711WT LED printers are excellent choices for printing full color dark t-shirt transfers on dark  apparel.

They produce brilliant color and opaque white much more efficiently  than white ink direct to garment systems–and for a lot less money. They use innovative two-step self-weeding transfer papers and work with a variety of popular graphic design platforms. There are some important tips and techniques you’ll need to know in order to get the most out of this promising new technology. Our Basic Guide to OKI WT printers is the place to start.

This OKI WT Beginner’s Guide  covers the basics of:

  • Selecting the best paper
  • Setting the printer
  • Preparing your artwork
  • And we’ll wrap it up with a few troubleshooting tips for fine tuning your transfers.

Two options for Two-step Transfer Paper

We have two paper options for decorating dark garments with OKI WT LED printers. Both papers are similar. Each sheet of paper is two parts; an imaging sheet and a transfer sheet. The imaging sheet is coated with a special polymer. You print your graphic on the imaging sheet, then place it face to face with the transfer sheet and press them together.  When you separate them, the transfer sheet removes the polymer coating from the un-printed areas of the imaging sheet.  When you press the imaging sheet to the garment, only the toner is transferred to the shirt. This is essentially the same process used to decorate dark garments with the GO UNO or OKI C831-TS. For a video demonstration of this process, please view segment five of our GO UNO Webinar.

The difference between the way these papers work with the C831-TS and OKI 920 WT and OKI 711WT is that the OKI WT printers add a white layer over the Cyan, Magenta and Yellow toner. Since the image is printed in reverse, the white layer is applied on top of the color layer. When the imaging sheet is pressed to the garment the white topcoat becomes a white under-base that serves as a barrier between the color of the fabric and the process colors in the printed image.  Got it? Good! So, there are two paper options for this process; Neenah Image Clip Laser Dark and Forever Laser Dark. With either paper, the first step is to press the imaging sheet to a transfer sheet. This removes the polymer coating from the unprinted areas and coats the toner to adhere it to the garment. Separating these sheets with a cleanly coated, usable image can be tricky. There are several factors involved including the quality of your heat press (see below). One thing we’ve learned is that this step works much more consistently if the lower table of the press is pre-heated. Otherwise the papers will begin to cool while you’re separating them and cause frustrating inconsistencies. Pre-heating the platen can make a world of difference, whether you use Neenah Image Clip or Forever Laser Dark (Click here for a more in-depth look at why this works). Having said that, you might wonder which one is best for you.

  • Neenah Image Clip Laser Dark works well,  but has a few drawbacks.  The heat press temperature setting must be increased from 250° to 375° between step one (pressing the imaging and transfer sheets) and step two (pressing the imaging sheet to the garment).  In some shops, that can produce unnecessary down time while the press heats up. Image Clip Laser Dark also has lower flexibility than the alternative, so it’s more prone to cracking after the transfer is applied. And it costs much more than the Forever Laser Dark solution. Neenah’s advantage is that it works on both the WT printers and the GO UNO/C831-TS CMYK laser printers, so it’s a more versatile product.
  • The Forever Laser Dark A-Foil and B paper combo  works same way as the Image Clip Laser Dark, but both steps are performed at same temperature, so there’s  not downtime waiting for the press to heat up.  It’s also easier to get consistent application of the adhesive layer.  The imaging sheet is transparent, so it’s easier to place your transfer exactly where you want it on the garment.  The A Foil sheets and B Paper are sold separately. But the combined cost of 11″ x 17″ packages of A Foil and B Paper is still $140 less than Neenah Image Clip, so it’s also more affordable. For more about the features and advantages of Forever paper, please click here. For media weight settings and more application tips, please click here for  the full Forever Laser Dark instruction sheet.

White toner setting:

One of the adjustable limits on the OKI WT printers is a white toner density setting. The range is from +3 to -3. The +3 setting produces the densest,  most opaque white. Since the purpose of the white toner is to offer opacity to support vivid color on dark fabric, one would assume that the brighter and denser the white layer is, the better the transfer will be. To paraphrase and old show tune, it ain’t necessarily so.

Actually Graphics One recommends the lowest setting, -3. Why is that? In the words of Graphics One laser transfer product specialist Eleni Barefoot,  “This is because white toner actually has a higher melting threshold than the CMY toners, and as such, takes a bit more heat to really integrate into fabric. Less ‘density’ or thickness helps with this.”

So the lower density setting makes the transfer softer. And soft transfers are what most people want to wear. There is another benefit. Eleni adds, ” Toner adhesion is the basis for maximizing durability and is inversely correlated with the density levels (more density, less adhesion) which is why we recommend decreasing the density level for white.”  In other words, The lower density setting on the white toner makes the transfer last longer in terms of wash and wear. A properly applied WT transfer will last for at least 20 washes; probably more. Increasing the white toner density might make the transfer marginally brighter, but it will be less durable.

Art preparation

Before you can transfer anything, you have to design an image. One of the most common questions we receive from people considering an OKI WT printer is how to prepare the artwork. In order to print on dark garments with white toner, your artwork must include a white element that the printer can interpret as a layer.

FIG 2: Here we see the white layer and black substrate layer in a Photoshop design. The black layer isn't sent to the printer.)

FIG 2: Here we see the white layer and black substrate layer in a Photoshop design (The black layer isn’t printed).

The recommended solution for creating WT transfers in Photoshop is to create a duplicate layer of the colored object layers and fill it with white. Make the background transparent. Then select it with the magic wand, invert the selection and use the Path tools to convert the selection into a clipping path. Save the path, then save the image and send it to the printer. The OKI WT print driver will read the clipping path as the white layer. Please Click here for step by step instructions.

When you’re designing graphics for black or colored shirts, it’s always a good idea to add a bottom layer matching the fabric color to help you visualize how the graphic will look on the garment (See Fig 2). In Photoshop, turn off visibility for that layer before printing.  And no matter what application you use, remember to flip or “mirror” the image before printing, or activate the mirror function in the printer driver. If you can read the text on the sheet that comes off the printer, it will be backwards on the garment. And vice versa.

Other application tips

Once you’ve mastered the design phase, there are a few other wrinkles to figure out in printing dark t-shirt transfers. Here’s a quick list of things to remember

  • Swing away heat presses work better because their vertical closing motion produces even pressure across the transfer.  Clam shell presses close at an angle, putting more pressure at the back of the platen than the front. If you must use a clamshell, place the transfer at the back of the table to maximize pressure.
  • It’s easier to separate the imaging and transfer sheets at the end of step one if they’re not exactly the same size. (This is why the 11″ x 17″ Neenah Image Clip Laser Dark transfer sheets are about 1/4″ smaller than advertised).  If you’re using Forever Laser Dark, clip a corner off of the B Paper sheet before you press them so you have something to grab to pull them apart.
  • Fine tuning the time and temperature. If your transfers are not separating cleanly and completely at the end of the first step, you may need to cook them a little longer. An extra ten seconds and/or ten degrees should solve the problem. This is especially helpful when you have several small images on one sheet. Before you take these extra steps, it’s a good idea to make sure the output from your heat press is correct. Click here to find out how.
  • Wear gloves. At the end of step one, the paper is rather toasty. The peeling must be done very quickly while the toner is warm. Time wasted playing hot potato with a fresh transfer can affect quality. Wear at least one glove so you can handle the freshly pressed sheets with confidence.

There are a lot of variables with laser transfer, even more with the two-step, white toner process. But if you choose the right paper, dial in the white ink density, setup your artwork correctly and fine tune your heat press, you’ll soon be cranking out stunning and highly profitable, full color transfers. These guidelines will help you get started more quickly, but they are by no means all there is to know about white toner laser transfer.  If you come up with a different way to prepare artwork that you’d like to share, feel free to offer it in the comments.