Screen printing is a popular printing technique that involves pushing ink through a stenciled screen onto a surface. It is a versatile process used to print designs, patterns, and images onto a wide variety of materials like paper, plastic, wood, glass, metal, and fabric. There are several different types of screen printing processes, each with their own advantages and best uses.
1. Flatbed Screen Printing
Flatbed screen printing is probably the most common and straightforward type of screen printing. It uses a flat stationary screen and works well for printing flat objects like posters, signs, and textiles. The main components of a flatbed screen printing setup are:
- Screen – A finely woven mesh stretched taut in a frame. The areas that will be printed are left open, while the rest is blocked off.
- Squeegee – A rubber blade used to force ink through the screen.
- Ink – Special screen printing inks are used for their viscosity and quick drying properties.
- Print surface – This sits beneath the screen and gets pressed up into contact with it during printing.
To print, the screen is lowered onto the print surface. Ink is placed at one edge of the screen. The squeegee is then dragged across the screen, forcing the ink through the open areas of the mesh. The ink transfers through these openings and onto the material below. The screen is then lifted and the process repeated for multi-color designs.
The advantages of flatbed screen printing include:
- Versatile for printing on a variety of flat surfaces
- Relatively simple setup and process
- Can print multiple copies quickly and efficiently
- Allows printing of fine details down to 65 mesh screen
- Cost effective for shorter print runs
Flatbed screen printing is ideal for printing things like t-shirts, posters, decals, labels, and textile yardage.
2. Rotary Screen Printing
Rotary screen printing uses cylindrical screens that rotate during the printing process instead of flat stationary screens. The rotating screens are much more efficient at printing high volumes. The main components of a rotary screen printing machine are:
- Rotary screen – A seamless nickel metal cylinder with the design etched into it. The non-printing areas are plugged.
- Squeegee – Inside the screen, this forces ink through the open design areas.
- Ink delivery system – Supplies ink into the interior of the screen.
- Print material – Feeds through on a conveyor below the rotating screen.
As the cylindrical screen rotates, ink is pumped into the interior of the screen. The squeegee forces the ink through the open areas of the screen as it contacts the material. This high speed and repeatable process is ideal for producing high volumes of printed products.
The advantages of rotary screen printing include:
- Extremely high productivity for long print runs
- Consistent, high quality prints even at high speeds
- Great for printing onto continuous surfaces like fabric, wallpaper, and giftwrap
- Can print finer details down to 135-165 mesh screens
- Low labor requirements compared to flatbed printing
Rotary screen printing is commonly used for long print runs like rolls of fabric, wallpaper, and continuous surface printing.
3. Pad Printing
Pad printing is an indirect offset printing process well-suited for printing onto curved, uneven, or complex shaped objects. An image is transferred using a flexible silicone pad. The main components are:
- Cliché – The flat printing plate that forms the image.
- Pad – A soft silicone pad that picks up an image from the cliché.
- Ink cup – The pad releases the image onto this inked surface.
- Print object – The surface that receives the transferred print.
During printing, the etched cliché is inked. The pad presses onto the cliché and picks up the image. The pad releases the print onto the object to be printed. This indirect offset process allows pad printing to print onto 3D surfaces.
The benefits of pad printing include:
- Ability to print onto curved, textured, and complex shaped items
- Ideal for printing on products like medical devices, electronics, pens, and hardware
- Relatively simple and affordable setup
- Prints very fine details down to 150 lpi / 120 microns
- High quality and durable prints
Pad printing excels at printing onto challenging surfaces like golf balls, medical tubes, pens, toys, and hardware.
4. Inkjet Printing
Inkjet printing propels precision droplets of ink directly onto a substrate. There are two main technologies:
- Continuous inkjet (CIJ) – Constantly jets a stream of ink droplets and electrostatically controls which ones reach the print surface.
- Drop on demand (DOD) inkjet – Only releases ink droplets when needed for imaging. Two common DOD methods are piezoelectric and thermal.
Inkjet inks are specially formulated for fast drying and adhesion onto the print material. Inkjet printing is highly customizable on demand and ideal for variable data printing.
The advantages of inkjet printing include:
- High quality digital printing
- On demand customization
- No plates or screens required
- Cost effective for lower volume production
- Very fine print resolution
- Wide range of ink formulations available
- Prints onto a wide variety of materials
Inkjet printing is widely used for graphic arts, signage, packaging, textiles, product decoration and marking.
5. Thermal Transfer Printing
Thermal transfer printing uses heat and pressure to transfer ink from a carrier ribbon onto a surface. There are two types:
- Resin ribbons – The print adheres to the material and the ribbon backing is peeled away.
- Wax ribbons – The printed wax is thermally transferred but the backing remains.
Thermal transfer printers use either a thermal printhead or a mechanical stylus to heat precise spots on the ribbon, causing the ink to melt and transfer. This digital process efficiently prints variable information like barcodes and labels.
The benefits of thermal transfer printing include:
- Flexibility to print onto many materials like plastic, wood, glass, and metal
- Ideal for printing variable data like barcodes and serial numbers
- No need for plates or screens
- Low equipment investment costs
- Good print durability in many applications
Thermal transfer printing is commonly used for product identification, coding, marking, and labelling applications.
6. Foil Stamping
Foil stamping transfers metallic, pigment, or holographic foils onto materials using pressure and heat. A metal die presses the foil onto the surface, bonding it using heat and pressure. The main components are:
- Foil material – Thin metalized film or pigment coating on a carrier.
- Metal die – A heated engraved die that transfers the foil onto the material.
- Print surface – Where the foil ends up bonded.
- Machine – Applies precise pressure and heat.
The foil separates from its carrier and bonds to the receiving material beneath the die. Foil stamping produces brilliant reflective and holographic effects.
The benefits of foil stamping include:
- Dramatic metallic, reflective, holographic finishes
- Great for high value decorative effects
- Works on paper, leather, plastic, wood, and textiles
- Durable and tamper-resistant results
- Wide range of colored, pigmented, and metalized foils
Foil stamping excels at eye-catching decorative effects on packaging, books, greeting cards, textiles, leather, and awards.
| Printing Process | How it Works | Typical Uses |
|---|---|---|
| Flatbed Screen Printing | Ink forced through stenciled screen using squeegee | T-shirts, posters, decals, packaging |
| Rotary Screen Printing | Ink transferred through rotating cylindrical screen | Wallpaper, fabric yardage, giftwrap |
| Pad Printing | Indirect offset print using silicone pad | Medical devices, electronics, pens, toys |
| Inkjet Printing | Precise ink droplets sprayed directly onto material | Signage, packaging, graphics, textiles |
| Thermal Transfer | Ink transferred from ribbon using heat printhead | Product coding, barcodes, labelling |
| Foil Stamping | Foils bonded using heat and pressure | Packaging, greeting cards, awards |
Summary
There are six main types of modern screen printing processes, each with their own unique advantages:
- Flatbed screen printing is versatile, simple, and great for printing posters, textiles and other flat items in shorter runs.
- Rotary screen printing is an efficient high volume process ideal for long continuous runs like fabric yardage.
- Pad printing uses a flexible pad to print high quality images onto challenging curved and uneven surfaces.
- Inkjet printing provides on-demand digital printing with variable data onto all kinds of materials.
- Thermal transfer printing is fast and well-suited for product coding and identification.
- Foil stamping creates brilliant reflective metallic and holographic effects for packaging and high value decor.
Understanding the different screen printing techniques is important in selecting the right process for a given print job and final application. Factors like print run length, surface material and geometry, image resolution, and cost all impact the optimal choice of printing method.
