ImagesMagUK_June_2024 JUNE2024 images 69 TIPS & TECHNIQUES need a tension meter. I know, I know, you keep meaning to treat yourself – well, hopefully this article will help convince you! Get a decent quality one. The Saati digital meter in the picture is, in my opinion, the Rolls Royce of the tension meter world (yes, I’m very proud to say it is mine!), but it costs several thousand pounds. The Newman meters are very good, and about a quarter of theprice. Buy one new, look after it, never leave it out of its box and always lie it on its back when you’re not measuring mesh with it. Your shiny new toy has arrived – let’s define some useable tensions here. Years ago, when we first adopted the Newman Roller Frame system at Phantom, we were trying to make screens with 77 and 90tpc (threads per centimetre, aka T) meshes at around 40Nm (Newton metres). These printed just great, but oh my goodness we were busting a lot of mesh! They were way too fragile for the rigours of a busy shop. Here’s what I’ve found to be good, workable tensions for T-shirt printing over the 20-odd years that we’ve been paying attention to tension: ■43/55T mesh at 35Nm ■62/77/90T mesh at 25-28Nm ■100/110/120T mesh 20-22Nm These tensions give you all the previously mentioned benefits but are also real-world robust. But how do we ensure this is what we’re getting? We need to be using good quality frames, and we need to decide if we’re going to bring stretching in-house or, if not, we need to make sure we have a good dialogue with whoever stretches our screens. If you’re outsourcing, make sure you specify a high quality mesh – they are not all created equal. Although everyone these days is using mono-filament polyester mesh, they aren’t all capable of the same stability (low elongation) at higher tensions. It comes down to price. The top brands for screen mesh, in my opinion, are Saati (Italian), Sefar (Swiss) and NBC (Japanese). Ask which brand mesh your screen-stretcher uses, and then ask them to produce your screens at around your specific tension. To be sure we’re being fair to whomever we are sending old frames for restretching, we need to make sure the frames are capable of holding the tensions we’re asking for. Cheaper frames have a smaller box section and thinner wall thickness, meaning they tend to bow excessively, causing loss of tension. For T-shirt frames (23 x 31” or 23 x 36” is standard for autos) the box section should be 40mm x 40mm with a minimum wall thickness of 1.6mm. At my shop, ours are 40mm x 40mm with a 2mm wall thickness, because then it will hold better tension for longer. Your other option is to stretch inhouse either using a retensionable frame system, such as Newman or Shur-Loc E-Z, or buy a set of clamps and restretch static frames. Newman Rollers I love Newmans, and we used them for about 18 years. They need their own pneumatic stretching table, which can become tricker to use as your frames become older and less silky-smooth than when they were new. Shur-Loc E-Z The Shur-Loc system is less fiddly but also less ‘dial-able’ in terms of your finished tension. They use premade mesh panels, which are very convenient, but a lot more expensive than buying mesh on a roll like you do with Newmans. Clamps A set of clamps is a wonderful addition to any shop. We got some about five years ago. Everyone can use them easily and they produce great results on static frames. The downsides are it’s a huge investment for the clamp system, and you’ll need grinding tools for the frames, plus the job requires glue, and it uses up a fair bit of space. In many ways, it’s easiest just to know what you need and make sure your screen supplier can deliver it. Profitable and enjoyable I know screen tension is an aspect of printing that is often ignored and overlooked. It’s one that many printers feel doesn’t apply to them because they don’t print intricate jobs, or simply because they have never worried about it and so don’t see the need to start now. But here’s the thing: improper and low screen tensions are at the heart of most of the day-to-day problems we face in getting our print jobs doneefficiently, profitably and to a professional standard. As screen printers, we all have our workarounds for dealing with persistent problems. But surely we’re better off finding the root cause of the issue, dealing with it at source, and never having the problem again? How much longer are we as managers going to watch our staff struggle with misunderstood problems, losing valuable time and potential for profit, and eventually leave us for a job elsewhere because they are sick of constantly putting out fires? Shops that understand and are on top of the screen tension issue are shops that are profitable, organised and enjoyable places to work. Let’s stop burying our heads in the sand when it comes to this key factor of our process. Will says the Saati tension meter is his top, albeit pricey choice