To help you understand the time and care we put into every print run we thought it would be helpful to give a basic overview of what happens everytime we print an order. This will help you understand some of the terminology we use in the screen printing industry and help you understand some of the possibilities and limitations of the process. It will also give you a better understanding of the reasons for minimum order quantity requirements and the reason that the price per item is lower when you order higher quantities.
This is a description of the garment screen printing process. The process for printing paper flatstock is identical up until the actual press setup and printing.
How It's Done
Once you have given your approval on the finalized artwork we begin the process of separating the colors in the design. Each color in the design is printed out on a clear film positive in solid black. One piece of film is needed for every color in the design. These film positives all have registration marks on them that line up with one another to assist in lining the finished screens up on the printing press.
Once the films are output we check them on our light table to double check details and make sure they all line up correctly.
Screen printing is essentially a stencil printing method. The stencil is a photosensitive emulsion that is coated over a monofilament polyester fabric that is called a "mesh" in the screen printing industry. This mesh is stretched extremely tight onto a metal frame. This combination of mesh and frame is what is called a "screen."
The next step after outputting each color in the design onto separate films is to coat the screens with photosensitive liquid emulsion.
Once this emulsion has thoroughly dried in a darkroom the film positives are taped onto the screens in the same location. The screen is then laid onto a vacuum top light exposure unit. The vacuum pulls a rubber blanket down over the screen to make solid contact between the glass, film positive, and screen. The exposure light is then turned on for a set amount of time to expose the light sensitive emulsion. Every color in the design is put onto a separate screen.
Once the screen is exposed the film is removed and the screen is taken to the washout booth. Here we rinse the screen with water. Any areas that were exposed to light in the exposure unit have hardened and any areas that were blocked by the film positive remain soft and water soluble. These water soluble areas wash out of the screen mesh leaving the areas open. These open areas are what the ink will be sheared through to transfer your design to the garment.
The screen is then set aside to dry fully and the process is repeated for every color in your design. Once the screens are dry they are double checked on the light table to make sure all details have transfered fully. Any imperfections are touched up.
Now we are finally ready to setup the screens on the printing press! Each color in your design has it's own screen that must be taped up, setup on press, registered to the other colors, and printed. As you can see there is a lot of work that goes into the process before an item is even printed. This is why we have order minimums. It just would not be cost effective to go through this setup process for very small quantities. This also explains why the price is less per item for larger quantities. The time it takes to make screens and setup the press to print 12 items is the same amount of time to make screens and setup the press to print 100 items. So if you divide that time by 12 it will be more per item than dividing that same time by 100.
Each color in the design is then printed onto the garment with a rubber squeegee in a predetermined order that lines up to create the finished image. The garment is then removed from the printing press and placed on a conveyor that takes the garment through a heat chamber that heats the ink up to the proper temperature to "cure" the ink thoroughly. The heat causes a reaction in the ink that fuses it with the fabric and makes it washfast.
Your garments are then stacked by the dozen and by size and packaged for delivery/pickup.
The screens are then scraped of all the ink, which is returned to it's containers, and the screens are removed from the printing press. The screen is then "reclaimed" in our washout booth. Reclaiming is the term we use for removing all the tape, cleaning out the remaining ink residue, and removing the emulsion to bring the screen back to it's original condition. The screen is then degreased to remove any oils that would interfere with the next coating of emulsion and is set aside to dry. Once it is fully dry it is ready to be coated with emulsion once again and used for the next print job. Screens are not saved, but the film positives are filed away to be used again in the event of reorders.