The Technology Behind Simple Screen Printing

In the earlier days, silk was utilized as a screen for this conventional printing form. Therefore, the term “silk screen” came to be associated with screen printing. In the world of graphics, it is frequently referred as Serigraphy. After silk, polymer meshes were adopted in its place. With the development in printing technology and printing machines numerous advancements has taken place in the printing industry. And this applies to printing application in various industries like graphics, fabrics, etc.

What are the equipments used for screen printing?

Initially, the screen has to be finalized and mounted on an aluminum or wooden frame. Then the stencil is engraved on the screen to get the desired design. Depending on what is to be printed, the type of the ink has to be decided upon. The material to be printed upon also matters when you are selecting the ink and designing pattern.

In order to control the movement of the mesh, a rubber blade squeegee is fixed alongside. The material is held firmly by the machine base so that the screen produces the print without any disturbance.

Applications of screen printing

The material on which the printing work is done could be made of silk, cotton, paper, polyester, plastic, glass, metal etc. screen printing is used for printing on fabrics, posters, CD covers, t-shirts, snow board graphics, medical products, electronics etc. Screen printing can be customized to suit various marketing and advertisement printing needs.

Technique used for screen printing

The screen or fine mesh is fixed firmly on a stand. Then the stencil is carved out that depicts a particular pattern or design. This screen is fixed over the fabric or material to be printed. There is a fill bar which is used to fill ink into the stencil. The screen doesn’t come in direct contact with the substrate.

Then the screen is slid down slowly to conclude the infilling procedure which is steadied by capillary action. The movement is stabilized by the squeegee. Finally, the screen is moved up by the squeegee leaving behind the design created by the ink.

Cylinder, Flat-bed and Rotary are the three different varieties of press mainly utilized for screen printing purpose. Among these, Rotary is the most famous one.

Same screen can be used again for printing similar designs using different inks and material. However, for creating a different design, the entire screen has to be reclaimed. You have to change the stencil by using liquid or powdered stencil removers.

Stenciling is normally done by using photo emulsion technique which is a well established technique since the past 50years or more. Different types of inks are used for creating different designs with beautiful effects. Design pattern and flexibility depends on the material being used.

Plastisol is one of the most common inks used in screen printing. It gives a more durability and a beautifully plasticized texture. By enhancing the ink we can improve the quality of the print to a great extent, thus producing superior quality printouts.

Screen Printing at Home – Creating a Stencil With PhotoEZ

Screen printing your own t-shirts at home is fun, addictive and even profitable. However, traditional screen printing methods are complex, time consuming and require more equipment than you probably have readily available to you at home. PhotoEZ solve all these problems for people looking to screen print at home. PhotoEZ is a screen printing sheet that is ready for exposure and used in less than an hour. You will not need anything extra for this project other than things you already have available to you at home. This article will describe how to create the stencil using PhotoEZ and how to avoid costly mistakes.

Creating the Stencil

The steps:

1: Print out your design you want to screen print on-to a transparency

2: Place the transparency over the PhotoEZ silk screen sheet

3: Expose the screen to direct sunlight for 50 seconds

4: Soak the screen in water for 25 minutes

5: Rinse sheet removing the emulsion, revealing your design

6: Allow to completely dry before using

Step 1: Print your image out on a transparency.

You will need 8.5 x 11 transparency sheets. Transparency sheets for screen printing can be purchased from any craft store. It will be coated on one side. Make sure you printer will print on the coated side, it keeps the ink in place and prevents smearing. The directions you receive with PhotoEZ sheets say to print with your printer on the High Quality setting. This is not necessary, printing with normal setting works great. I have a HP inkjet printer, and printing the transparency on High Quality setting actually causes horizontal gaps lines which is not good for exposing. You also have the option of printing your image on 88 brightness paper, but if your design is more complicated, with a lot of detail, transparencies work best.

Step 2: Placing the transparency over the PhotoEZ silk screen sheet.

Prepare the screen by removing it from the sunlight proof ziplock bag and peal the plastic off the shiny side. PhotoEZ kits comes with a hard board and plastic covering to make exposing the sheet to the light simple, and to make sure the transparency doesn’t move. Place the PhotoEZ sheet on the board shiny side up, then place the transparency over top. Keep in mind that, when you screen print, the shiny side with be face down, so you should be looking at a reverse image of what you want printed at this point. Place the plastic covering on and clasp is all together. Cover it with the foam sheet to prevent exposing the screen before you can begin timing.

3. Expose the screen to direct sunlight.

Expose your screen to direct sunlight for about 50 seconds. Do not attempt to expose during over cast, or early in the morning or late in the evening. You will under expose the screen and it will be ruined. Don’t leave the screen in direct sunlight for more than 1 minute, or you will over expose the screen and you wont be able to wash out your design. If you have access to fluorescent lighting you can use this instead of sun light. Doing it this way takes a little longer, about 25 minutes, but it has a few benefits. First you can expose anytime during the day you like. Also you have less risk of over exposing the screen, and when it comes time to rinse the design it washes off much easier.

4. Soak screen in water for 30 minutes.

Allow the screen to soak in water for about 30 minutes. you can use a plastic organizational tub for soaking the sheet.

5. Rinse the stencil off in the sink.

A sink sprayer works best for removing all the excess emulsion. If parts are not washing away, use a paint brush and rub the area where the emulsion is not coming off and will come free easily. You may want to put the stencil back in direct sunlight. Placing the stencil back out in the sun allows it to fully expose and it will be more durable. Do this especially if you used fluorescent lighting to expose the screen.

6. Allow to completely dry. You can speed this up by using a hair dryer.

It might should like a lot of steps, but it is easy, and fast. Once you get the hang of it, you will be making stencils in no time and be able to start silk screen printing is less than an hour.

Screen Printing VS. Digital Printing – What’s the Difference?

For years t-shirt printers have used screen printing as their preferred method for printing designs onto t-shirts. The only other alternative used to be iron-on designs or transfers, which was a very different type of product. Many people remember the transfers from the late 1970s and early 80s as thick rubbery designs that would sometimes crack or peel. Another problem with iron-on was the fact that it was time consuming to do multiple t-shirts. Screen printing was a much more efficient process, allowing t-shirt printers to do multiple t-shirts faster while creating a higher quality shirt. Screen printing had long become the standard in the t-shirt printing industry. The standard until digital printing starts to evolve.

As the computer gained popularity in society, so did graphic design. The ability to design unique graphics on computers has become one of the most sought out skills in today’s job market. More and more people are using their computers to create unique t-shirt designs. Still, computer generated designs were still printed on shirts using the screen process until the rise of digital printing. The digital process is the new era of t-shirt printing, allowing a printer to print designs from a computer directly onto a t-shirt. Digital printing is the 21st century alternative to screen printing.

Faster and Cheaper

Printing with screens is still widely used by t-shirt printing companies and is still a quality process, but the digital process has quickly become the chief alternative for small runs. The set up for digital is much easier and cost effective. In the screen process one has to set up a screen for each color the design takes, which means that the more complex the design is the more screens the printer is going to need. This increases the manual labor which is going to increase cost. When a screen printer prices their t-shirts, they always charge more for more colors. With digital t-shirts there are unlimited colors and no screens, just one flat fee per t-shirt. Instead of setting up all the screens beforehand, the only set up digital requires is a pre-treatment of the t-shirt, which gives the shirt a solid base and prevents the digitally printed ink from smearing. This is a much less time consuming pre-printing process.

More Control

Digital printing offers much more control during the printing process than screen printing. Digital printing gives a printer the option of auto-matching ink. Instead of mixing inks, the screen printing way, ink matching allows the digital printer to print any color from the original design directly onto the t-shirt. The digital ink process makes it easier to print multi-colored designs digitally on t-shirts.

For a large order of t-shirts screen printing is still going to be the main option most t-shirt printers choose. The only downside of digital printing is the manufacturer needs multiple printers in order to speed up the printing process. Screen printing can print more shirts at a time, making them ideal for large orders. This is the main reason why digital printing hasn’t completely taken over the market. Some day most t-shirt printers may only do digital printing if printers become large enough and are able to handle bigger orders. Until then screen printing and digital printing will continue to work together. It will be up to the printer to decide what process is more efficient for each individual order.

However, digital printing is making stride. A decade ago digital printers were rare, now most t-shirt companies have a digital printer and use it for all single t-shirt orders.

A Beginners Guide to Screen Printing

There are a limited number of artistic activities around today that are as fun, and at the same time as challenging, as screen printing / silk screening. Screen printing requires a screen secured in either an aluminum or wooden frame, a screen printing press, a stencil, and inks in order to print your image onto your desired medium. Most screen printing set ups cost thousands of dollars for multi-arm presses and all of the required chemicals and inks, but there are also several ways to screen print on the cheap from your home.

When it comes to screen printing, there are a few basic materials that are necessary to begin printing. First, there are the screens. A screen consists of a fabric mesh that is stretched out on a wooden or aluminum frame, and the tighter the mesh is stretched, the better details will show up on the print. To burn your image for printing onto the mesh, you will need a stencil made of film positive or a transparent material such as the transparencies used on school projectors, a container of emulsion fluid, and a container of sensitizer fluid. Next up you will need a piece of glass that will fit inside the frame to cover the mesh, a piece of dark cloth (preferably black as you need to block out all light), and a 250 watt photo bulb lamp. Gloves, a water supply such as a garden hose with spray nozzle or a sink, gloves, an art squeegee and the actual screen printing ink are all that is left to get you on your way to printing your own custom apparel.

Now, when it comes to the stencils, there is a huge difference between what could be a great design and what could be a terrible design when printed. Images with large areas of contrast, such as vector images, show up really well when printed, where as designs with a lot of detail that is all over the place make it harder to print. Also remember that the more complex the image and the more colorful it is makes it more expensive and harder to print said design.

So once you have your design planned out, now it comes down to actually making the screen to print. First thing you are going to want to do is make sure the screen is securely fashioned to the frame. If you purchased a pre-made screen and this is your first time using it, you shouldn’t have any problems with this. If you are more of a DIY person and made your own screen, make sure the screen is stretched tight and securely fastened to the frame. Print out your design to make your stencil. Now it’s time to burn the stencil to the screen. You are going to want to mix the emulsion and sensitizer together, and then applying the mixture to both sides of your screen in a dark room, as the emulsion is extremely sensitive to light. Take your art squeegee and even out the emulsion so that it is distributed evenly. Leave the emulsion covered screen in a dark room or box for about 2 hours and the emulsion should dry without hardening (making it much harder to clean the screen out). After the emulsion has dried on the screen, place the screen onto a dark / black cloth, and then place the stencil onto the frame and the glass on top of the stencil on the screen. What you are going to want to do now is expose only one side of the screen to your 250 watt photo bulb light source, which will allow the emulsion to dry in about fifteen to twenty minutes. Once the emulsion has successfully dried, remove the glass / stencil and rinse off the emulsion using your water source. After you have allowed the screen to dry, you are good to start using it to print. It is highly recommended to use a screen printing press, which you can build yourself if you are more DIY inclined, or you can buy a single press for cheap at a local arts store such as Michaels. Secure the screen to the press, or if you are not using a press then place the screen onto whatever medium you are wishing to print. Pour a good amount of ink onto the screen, and use your squeegee to evenly distribute the ink throughout the screen while applying a good amount of pressure. At first you will see spots that you missed and you will have to reapply more ink, but don’t worry – practice makes perfect in the screen printing game and you will eventually find a good way to apply the inks.

When you are done, lift the screen and you are all done. Your custom apparel is done. Depending on the types of ink you used, you may have to wait a bit of time before the ink dries. Put the freshly printed shirts on a flat counter top where no one or anything will hit them and allow them to dry. When you are done with all your printing, you can wash out the screen / frame and repeat the steps to reuse them as often as you would like!