When the thought of this topic crossed my mind, my first instict was "no, not tackling that...too big", but then I reconsidered. Why shouldn't I drop an article on the basics of screen printing and how they evolve? I mean, the resources out there now can have someone pulling a squeegee within a few days and when they don't understand why their colors are orange peeling, they just google it. For those of us that learned on our own, without the help of the internet, it seems like an unfair playing field. That is, until you realize that all the youtube videos are actually your best friend as well. Nowadays, the print can really be made better by what we do in the art department.
Take in to example a recent favorite video of mine from Rising Sun Graphics I've done separations for years, but in our maket there's not a lot of jobs that require high end seps and when they have come along, I normally haven't employed the subtlte trick that you see in the video. It's not that I havn't done it, but after a while shops can become very production oriented and undbasing means....white ink. The video so brilliantly shows the benefits of non-white underbase in this scenario but it's important to note how the same on press principles are still needed to pull it off. We will address a few of these t-shirt printing basics below.
Printing t-shirts is like anything else, it evolves. Sure, there are the tried and true, long standing techniques that we always have to abide by, but the winds are changing and technology waits for no man. If you are familiar with the writer/philosopher, Ken Wilber , you may know about his idea of "Intregral Theory". As the theory goes, as systems evolve, they always transcend and include. We normally think that evolving systems completely destroy the old way, but the truth is that normally it solves old problems but also includes some basic building blocks of the old paradigm.
Like other evolutions, screen printing has primarily taken a process and evolved that process through technology. People in larger shops using automatic presses have finely tuned machines that have trascended their DIY, table top or manual forefathers. These presses run from, or a combination of electric motors and pneumatic systems. Depending on expense, they can also be running firmware in their control heads that literally control and keep track of everything that's happening with the job. Here are five manufacturers of automatic presses. Feel free to link others in the comments.
The M&R Companies
So, a few of the screen printing standards that have always been true when it comes to great prints are the same things that most smaller shops for go because of cost. Like anything on the planet, you get what you pay for so listen up!
First off, screen cleanliness and tension. I thought I would throw in cleanliness because most shops reclaim their screens. It is of great importance that the screen is cleaned with a Haze remover as well as a typical emulsion and ink remover in the process. The screen tension is the one thing that every shop should monitor. Poor tension will lead to a myriad of problems on press. A few of those problems may be but are not limited to; poor registration, poor ink deposit & pulling off of the previous wet color.
Secondly, squeegee sharpness. I have seen printers using sqeegees that are not only so old that their durometer is wrong, but knicks in them as well, creating lines in the print. Replacing squeegees is realtive cheap and quick, so if you don't have a squeegee sharpener, buy new blades periodically.
Squeegee stroke pressure and speed are job dependant. Mesh count & halftone detail are couple of considerations when determining these two variables. I can tell you though, if you're screen printing press is not calibrated/level, you will never get accustomed to what is right for any particular job. For example; if a pallete is unlevel, it may seem as if the print needs slower and more forceful pressure to clear the screen. This is dangerous, because the problem could be a low tensioned screen! Let's assume that you go slower with more pressure and it clears. The very next print could be a blob or possible close up some high percentage halftones.
The good news is that technology has evolved to account for some of these potential problems of the last stage in evolution. Various meters are on the market now to test for these obstacles. Now, in the case of press calibration, a technician is required unless you already have working knowlege of the process. Here is a great video from Catspit Productions that covers some of the meters that you will want to have in your shop.
The next evolution of screen printing is definitely driven by our ability to make everything computer driven. The latest iteration of Direct to Garment technology (computer to t-shirt by way of ink jet print head) is constantly making steps forward. Albeit still in it's baby stages when it comes to productivtiy and cost per shirt, it's place in the future of t-shirt printing is definitely being staked.
PersnickeTEES wants to hear you feedback, comments and advice for other printers out there. When we share our knowledge, we transcend the fear thinking that keeps us from providing consumers with a great product at competitive prices. Let's thrive together!