How To Screen Print With Plastisol Heat Tranfers
Screen printing heat transfers can seem daunting but in reality it’s actually fairly easily. If properly produced, plastisol heat transfers can last almost as long as a direct print and can be much easier to apply in certain scenarios. Screen printing your own heat transfers can be a feasible solution for many scenarios a screen printer often faces. Here are a few ways screen printing your own transfers can help your business!
- Pre printed designs for events: I can’t tell you how many horror stories I have heard of customers printing a thousand shirts, then going to an event and selling only a few hundred. Screen printing transfers for the event and heat pressing it at the event for the customers selected size and color is simple, easy, and can save you a ton of money!
- Decorating hats: Have you ever tried screen printing a hat? Not fun! However printing a transfer on a flat piece of transfer paper and then using a cap heat transfer press to transfer the design onto the hat is actually very easy. Also since hats are not often washed, there is really no difference in the longevity of the print.
- Names for sports: Rather than exposing a screen with a bunch of names on it and having to custom place it over t-shirts for the correct position, why not screen print names on a heat transfer sheet, cut them out, and then just heat press them onto the shirt. You can even screen print numbers and heat transfer those as well. With numbers however using a vinyl plotter for printing numbers with heat transfer vinyl may be a little easier.
- Blocked hole jersey printing: Some customers prefer that the holes in mesh jerseys are blocked, instead of trying to pile ink on top of the jersey, use a heat transfer to keep the ink up on top of the mesh.
- Blanket customer orders: If you have a customer that wants to pick up shirts as they need them off to print transfers for them and store them so that they can be transferred at a later date when the customer desires.
Ok, there are many reasons to screen print heat transfers, but what do you need and how do you do it? This quick guide will walk you through the basic components and how to of screen printing your own heat transfers. This just covers the basics and is enough to get you started, Ryonet is also in production of a screen printing heat transfer DVD which will go into deeper explanation and more in depth training.
How do screen printed heat transfers work? A plastisol heat transfer can be screen printed with standard plastisol ink or a special plastisol ink specifically designed for screen printing transfers. If you are not solely screen printing transfers you can use your standard plastisol ink. The ink is printed in reverse (reverse image) onto a heat transfer paper that has a special coating on it which will release the ink once heat pressed. After the ink is printed an adhesion power is typically sprinkled onto the wet ink which helps it to adhere to the shirt during heat pressing. The ink is then gel cured but not cured completely. Once gel cured the transfer can be heat pressed onto a garment at any time.
What you’ll need:
- A screen: As we will explain later, when you screen print a transfer you typically need a heavier deposit of ink through the screen. We recommend using a 110 mesh screen but you can use anywhere between the range of 86-156.
- A dual edge coater with a round coating edge.
- Plastisol Ink – preferably opaque plastisol ink.
- Transfer Adhesion Powder which helps adhere the ink onto the garment.
- Plastisol Heat Transfer Paper. There are a few types of transfer papers available. Ryonet sells three different types of plastisol heat transfer papers, Transal Premium HOT PEEL, Transplit Hot Peel, and Transal Express Cold Peel. The difference between hot peel and cold peel is in the way is peeled and releases the ink. Hot peel transfers transfers (often called hot split transfers) need to be peeled immediately after heat pressing. The reason they are often called hot split is because they typically leave a percentage of the ink on the transfer paper as the ink splits during peeling. This is the reason why you need a slightly thicker coat of ink on the paper. Hot peel transfers feel soft on the shirt and are quick to complete. Cold peel transfers must be peeled when the shirt and paper have cooled down, they take longer because of the cool down time and are a little harder to use typically. Cold peel transfers do release almost 100% of the ink but the ink often feels a little rougher. The best of both worlds is a premium hot peel transfer paper, a premium paper releases most of the ink for the best opacity and coverage, is quick and easy to apply and peel, and is typically the easiest to use as well. A premium paper has a glossy coating on it that is specially formulated to release the ink under the heat press. Heat transfer papers range in price from $.12 – $.25 depending on the type and quantity purchased.
- And of course a heat transfer press.
1. Screen making: When making a screen for printing transfers you want to coat the screen with a slightly thicker coat of emulsion then you would typically use for printing directly onto the shirt. Use the round side of the scoop coater in order to achieve a thicker coat of emulsion on the screen. The reason you coat the screen slightly thicker is because you want a slightly thicker ink deposit on the transfer paper.
You also need to remember to reverse your image when exposing the screen, you actually want to screen print your image in reverse so it will show up correctly onto the shirt once it is reversed again during the heat pressing process. Instead of seeing your image correctly through the ink side of the screen, you will view your image correctly through the shirt or print side of the screen.
2. Screen printing: Screen printing a heat transfer is fairly easy. You need to set a standard off contact of 1/16″ and ensure this off contact is consistent throughout the screen. If you are printing only a few transfers you can use a small amount of spray adhesive to hold the transfer in place. However if you plan on printing a lot of heat transfers and multiple color transfers we recommend that you looking into a vacuum pallet that holds the transfer down with suction during printing. For printing multiple color transfer you do need to print in reverse print order (under base last) and flash between colors. Since this is a basics article we won’t get too in depth on multiple color transfers. To print you can use a standard 70 durometer squeegee. We would recommend using a thicker opaque ink which will hold up better during the transfer process verses a thin ink that is transparent. RyOpaque opaque plastisol ink works great for printing on transfers! After the ink is printed you want to sprinkle Transfer Adhesion Powder over the wet ink. You can do this by spreading out the adhesion powder in a big bin and just dipping the transfer paper into the bin picking up some powder, spreading it over the paper by moving the paper around, and then dumping it back into the bin. Be sure to tap the paper very well to get all the powder off the paper except where it sticks to the ink, if you not clear the paper well of the powder you will have problems with all the paper sticking to the shirt instead of just the ink. Transfer Adhesion Powder goes a long ways and is a must if you want your transfer to stick to the shirt.
3. Curing: When curing a heat transfer you do not want to cure the ink all the way. You basically want to GEL the ink so that you can heat press it later which will finalize the cure of the ink. To gel the ink you typically keep it under the heat for 6-10 seconds depending on how hot your dryer or flash dryer is. You want the ink temp to reach between 180 and 240 degrees. How do you tell if your ink is properly gelled and not under or over cured? A perfectly gelled ink should peel from the paper like the picture you see below. If your ink is under cured then ink will come off on your fingers when you try to peel it, if your ink is over cured then you will have to pick at it very hard to come off or nothing will come off.
Once you transfer is cured, you should store it in a dry temperature controlled area, it should last for over a year if properly stored.
4. Heat Pressing: This is typically the easiest part. We recommend setting your heat press between 330-350 degrees and heat pressing for 10-12 seconds with a medium pressure. A medium pressure means that you should press fairly firmly down onto the press when applying to the shirt. After the time has been completed, peel immediately or let the transfer cool depending on whether you have a hot or cold peel transfer. The tricky part is, if you let a hot peel transfer sit too long (you must peel immediately) the paper will not come off, and if you don’t let a cold peel transfer wait long enough, you’ll have the same problem. This is why I prefer using the Transal Premium HOT PEEL because I typically just peel the paper a second or two after it comes off the press, and it works almost ever time perfectly!
TEST AND BE PATIENT: Since everyone is using slightly different types of ink, curing units, heat presses and printing methods, you’ll need to test around your parameters to find out what works best for you. Go to Screenprint.com and check out our DVD’s on Plastisol heat transfer and more!