Industry expert Tony Palmer explains why even the best press operator can’t undo an error made in the screen room
Let’s set the scene: it’s Friday, the last day of the week. The next job on the press is a simple three-colour print on mixed shirts – a total of 82 pieces. It’s 2pm and the customer is calling at 5pm to collect. No problem. As you pick the screens up and start to place them into the press your mind is already racing to the time when you can turn othe lights and finally go home after another chaotic week. You start to click the screens in the correct order and select the correct blades, but when you run your fingers down the rubber edge you notice a small nick. No problem. You can swap it out and you’ll be ready to go.
In goes the underbase screen and, after trying to find a scrap of shirt to print on, you produce a print of the first screen in this ‘simple’ three-colour job. The white is a little dull but that’s probably just the first print, the ink is still a little sticky. You notice that the next colour is on a 43t mesh, but it should be okay as you’re only printing 82 pieces. The stencil department should have known to put this on a 90t, but you can cope: just flash it and it’ll hold, or use a harder blade, straighten the angle and back that pressure off. You’ve been doing this for years, you’re a good printer, you have skills. You’ve got this!
The third colour presents a different problem: the mesh is too high. It’s obvious that the stencil guy has got these two colours the wrong way round and this top white is not going to look too bright. The screen is taped really nicely for a change, but as you try to set it the micro adjusters reach the limit of movement. It needs to go just 1mm more to the left, but, as hard as you try, it just won’t go. After several attempts at bending things that shouldn’t be bent and exercising your extensive knowledge of swear words in various languages, it finally dawns on you that you have to move the other two screens. So the base is unclamped, moved 25mm over, a new scrap shirt is printed and the second colour lined up. It’s taken another 30 minutes, but you still have two hours left – loads of time to print 82 pieces. The press salesman says this press prints at over 1,000 an hour!
The first sample print comes off and it’s very close to being in register. So you do one more print just to clean it up. The white needs more punch, so you set a double stroke. It’s still not very bright, so you swap out the blade and hit it again.
The second colour rips off and you use words that you would never repeat in front of your mother.
The third sample print is looking good, but the edges are a little rough – that mesh is really too low but a flash cleans things up and the white looks better with three strokes. It’s only 82 pieces, it won’t take much longer.
Vibrant, accurate prints are easier to achieve if the pre-press team is on the ball
As the fifth test print comes off the press, you’re finally happy that the white is opaque, the second colour is clean and the print is looking good. But the ruler tells a brutal truth: the design is now 24mm off-centre. But you have the skills, you can do this; just load them all to the right a little, no problem, you’re a great loader. A seventh test print now gives you the correct position and, after marking up all the pallets, you can finally start this ‘simple’ little job. But, 20 shirts into the run, the second colour starts to bleed and it no longer looks as great as the strike off. So you stop the press, wipe under the screens, apply a little silicone spray. A quick preheat cycle keeps the flashes warm and off you go again.
Five shirts in and the sick feeling hits you: after the restart you forgot to load off-centre and the shirts you just printed are closer to an underarm print than a chest print. You stop the press and search the warehouse: what are the odds of a job for next week having the same colour shirts and the right sizes so that you can steal/borrow five replacements? You get lucky, and you have five new shirts ready to print. That’s when the sound of the second colour ripping off strikes a cold chill in the pit of your stomach. But you have the skills, you’ve got this. No problem. Sending the shirts round the press again makes the ones with a ripped off colour look great – too great! They look so good that you realise you need to send the whole lot round twice! So you print-flash-print, turn off head #4, turn on head #6, let them go around the press again. The shirts look fantastic!
It’s now 4:30pm, and there are only ten more prints to go. You try to work out how quickly you can fold and pack 82 shirts, when the buzzer on the front door announces the arrival of the customer. Luckily, he’s cool – he wants to see you print his shirts, and even offers to help pack them with you. So you try not to decapitate him with a rotating press and answer all the dumb questions that most people ask when in a print shop: yes it is warm, no I don’t notice the smell, yes that’s wet, don’t touch that and please stand back.
The last shirts are coming off and the customer points out a faint shadow on the side of the design. It’s in a straight line and it looks like a white haze on the left side only. You know exactly what it is: the stencil is breaking down after just 80 prints (well, it’s really 240 considering how many times you’ve sent this job around the press). Out comes the emergency tape. It takes real skill to cut through this tape into the exact reverse of the stencil, but you nail it – only three of the shirts need a clean and you have the skills to make this look easy. The last print comes from the press and the next hour is spent chatting to the customer while he helpfully tries to fold a shirt. Fortunately he didn’t notice you using a baby wipe to remove the haze from three more of these precious shirts. The job leaves an hour late, the customer is cool and the print looks great because… You have the skills. You’ve got this. No problem.
Poor pre-press skills cost money
Use a meter to check the screen tension
Invest in pre-press
By my calculations, printing 82 pieces as a three-colour job, on a machine that prints 1,000 pieces per hour, should take less than five minutes in total. Build in 10 minutes to set up and tear down, and the entire job should be on and off in 15 minutes. But the job I’ve described above took three hours – purely as a result of poor pre-press. Pre-press describes everything that happens before a job hits the press. So if this job was planned to take only 15 minutes in production, then you need to work out the time and effort invested in the preparation of the job. Artwork can take at least an hour to draw, size, label, create a base and create a visual layout. Screen preparation is time consuming – correct degreasing, good coating methods and exposure procedures can take precious time to complete. The three-colour job described probably had a good three-to-four hours spent on it in pre-press, but only 15 minutes on press, so which area should have the most investment?
Process repeatability
Capital equipment can greatly increase pre-press quality as it ensures repeatability and consistency. Automatic coating machinery may sound like an expensive way to perform a task that can quite easily be performed manually, but the correct machine will give a measured and repeatable stencil every time, irrelevant of the operator’s skill level. Automatic developers are often described as expensive jet wash machines, but they give a repeatable, consistent result, again removing the variance of the skilled operator. Precise exposure machines with correctly calibrated exposure times can eliminate press problems before they happen. Imaging devices are rapidly changing the way we make screens: the next generation use lasers and no consumables to only expose the areas we need. This machinery allows us to repeatedly image a screen in the same place at the same quality every time, again removing the unquantifiable variable – the person pressing the buttons.
More haste, less speed
Screen print machines are now operating much faster than the capability of the operator, so the only way to produce more pieces is to stop less often. So many print shops are now embracing ERP (enterprise resource planning) systems that monitor and predict times and job statistics, but I would rather run a 1,500-piece, trouble-free job at 500 pieces per hour for three hours than run a troublesome job at 1,000 pieces per hour for 20 minutes, stop to solve issues, run again at 1,000 pieces per hour, run into more problems, stop to repair pre-press failures, then run again at 1,000 pieces per hour. When you analyse the data it becomes obvious that the three hours at 500 per hour were actually more efficient than the ‘faster’ job: the operators were much more relaxed and the 1,500 pieces actually felt easier to produce.
There are lots of old sayings that could be applied to this theory: ‘more haste less speed’, ‘the tortoise and the hare’, ‘fail to prepare and prepare to fail’. The important lesson here is that pre-press takes up more time than production, so there should be more investment in both time and money to ensure we all work smarter, not harder. As a printer, you only make money when the squeegees are moving. So don’t focus on moving them faster; instead, focus on keeping them moving slower for longer.
Tony Palmer has been in the garment decoration industry for over 30 years and is now an independent print consultant working closely with print shops to get the most from existing processes and techniques. Tony is passionate about keeping and enhancing production skill levels within in the industry. He is the owner and consultant at Palmprint Consultants, offering practical help and assistance to garment decorators all over the globe.
