Learn How To Screen Print Tee Shirts At Home

The 2 most popular types of emulsions on the market today seem to be dual cure and photopolymer. Each of the 2 different emulsions have very different characteristics. These unique properties makes it possible to use either emulsion to adapt to your own printing situation. The type of art , film and even the screens you use may be partnered up with the right emulsion to give you better results and an easier time printing.

Rather than try to explain all the different situations you might use either emulsion, I will describe the different characteristics that I think will affect you most at home. There are three points I will make about each of the 2 emulsions. Hopefully you will be able to digest this information and apply it to your own printing needs. You should be able to do this easily.

Dual Cure Emulsion

One of the first things to note about dual cure emulsions and photopolymers is that the shelf life is very different. A dual cure comes with the sensitizer separate and has to be mixed into the emulsion base. As soon as this is done, the clock starts ticking and most dual cure emulsions will have a standard shelf life of about 1 month. This is giving that the ambient humidity and room temperature are not extreme in variances. Temperature and heat exposure will affect all emulsions and their shelf life. That being said, photopolymer emulsions may have a shelf life of up to 1 year and they do not need to be mixed. Shelf life may be the single most important factor in purchasing an emulsion. If you can’t use the emulsion before it spoils, then it may be a good idea to go with longer shelf life.

The second major concern is the exposure latitude of the emulsion. This refers to the emulsions ability to give you a good exposure, and stencil, within specific time interval. Dual cure emulsions have a much wider exposure latitude which means they are forgiving and will make a good stencil at a wider range of exposure times. This means that it will be easier to burn a screen, especially with detail, using a dual cure emulsion. That also means it will work well with inferior films or films that are not dense enough to block all of the exposure source light. Dual cure emulsions will work well with vellums, transparencies and other home made film positives.

On the other hand, photopolymer emulsions need very, very dense or opaque film because they have a smaller exposure latitude. With a photopolymer it is important to come as close as possible to the perfect exposure time. If this exposure time is long enough for light to pass through your film and semi cure the emulsion, then you will have trouble getting your stencil to wash out properly. That’s why a completely black film positive is needed to block all of the exposure source light. Therefore if you are working with inferior film positives, you may want to consider using an emulsion with a wider exposure latitude.

The last thing to consider is the exposure time itself. Dual cure emulsions may have a wider exposure latitude but they also take longer to expose and cure than photopolymer emulsions. A screen with film that may take 40 seconds with a photopolymer emulsion will take perhaps 3 minutes on the same light table for a dual cure emulsion. This is just a “guestimation” being that I am not actually comparing real results but they are for illustrative purposes. One reason you may want to consider this when buying emulsions is that heat may cure emulsions. If your light source puts off a lot of heat, it may cause problems with a longer exposure time, savvy?

So here it is:

Dual Cure Emulsions – wider exposure latitude, more forgiving with incorrect exposure times and poor film positives, only last about 1 month on the shelf, needs to be mixed with sensitizer.

Photopolymer Emulsions – smaller exposure latitude, less forgiving with incorrect exposure times and poor film positives, lasts up to 1 year on the shelf, does not need to be mixed with sensitizer.

Now you have some technical information about screen printing emulsions that will help you in your screen making process. Please visit the Catspit Productions website to learn all about the screenprinting process.

Learn how to screen print with Catspit Productions, LLC!

Here we go! As I have promised; 1 screen printing video each Monday until December 20^th. I think I can, I think I can…

A brand new screenprinting video has been uploaded to YouTube. This one is called “How To Screen Print: Safelights For Screen Making”. This is another quick tip video in which I discuss safelights for screen making. Believe it or not, many people struggle with this and often expose their screens to unnecessary daylight. This can cause many strange and bewildering problems during screen making. I find it is always best to eliminate variables even when you may not be sure if the variable is contributing to a particular problem.

Remember, emulsions are sensitive to ultra violet light or UV light. Yellow filters will block UV light and red ones also block UV light. Therefore a red or yellow filter on any light will do or you can buy a red or yellow light. Certain amber or orange looking filters will work as well.

Learn how to screen print with Catspit Productions, LLC!

I have teamed up with Joe Wicked from YouTube to create an entirely new Catspit Productions logo. This is a very cool new logo that I will be calling the “Tom Cat” logo. I really love this concept that Joe did for me. I love the cat head as it reminds me of old Tom form Tom & Jerry. That was one of my favorite cartoons as a kid and I still watch them today whenever I have a chance.

Joe Wicked's "Tom Cat" Logo

I received the raw artwork from Joe last week and I am in the process of scanning it. Then it has to be redrawn in the computer and made into vector artwork. This is a process which will make the hand drawn art digitized and able to be manipulated and color separated. Speaking of which, if you need to get some artwork converted into vector, visit the Artwork Services page of the Catspit website and check out the information there.

I have added the service of vector art conversions to help out the many beginners in the screen printing industry. Artwork is the single most important phase of creating a screen print. If your artwork is poor then no matter how good you are at screen printing, the print is going to turn out badly. It is imperative to understand how to create artwork for screen printing but the first step in doing that is working with vector art and understanding how to create it.

Since most of us are not professional graphic artists, including myself, having a service which can convert hand drawings and other scanned artwork into true vector art is a great help. I can use a low res JPEG, PNG, TIFF or any other digital graphic format readable by the PC to make vector art files in EPS format.

I am excited to offer this new service and when the new Tom Cat logo is done I will post the vector image to show everyone the results of this service. You can go to the Artwork Services page and see a simple example of the conversion right now. Thanks a bunch Joe! I can’t wait until it is ready for printing.

Learn how to screen print with Catspit Productions, LLC!

A new screen printing video has been uploaded to YouTube. This video is about using micro registration on press to register screens with a multi color job. It covers micro registration and how it is used in more depth than I have done before. I know I addressed this in the tee shirt press video but I thought I would focus on it and perhaps make it a little bit more clear for some.

The new screenprinting video is called. “How To Screen Print: Using Micro Registration”. You will get to see a close up view the print head as I demonstrate the movements of the head with micro registration. You will also get to see an example of why it is so important to keep your press very clean and well lubricated. For all of you who asked to see problems arise in a video, well this one sort of has a bit of that. You will definitely understand why I say good, functional equipment is a must.

I plan on releasing 1 video each Monday, starting today, all the way through December 20^th. I need your help in keeping the video counts rising on each new video. YouTube likes that…LOL. Can you all keep up with me?

Thanks for reading! Learn how to screen print with Catspit Productions, LLC!