Screen printing is an ancient art form. It's an effective technique for creating vibrant canvases, posters and artwork but the method can also be used to print fabrics and textiles. The technique uses mesh to transfer ink, except in areas made impermeable by a stencil. The process is sometimes called serigraphy or silkscreen printing.
There are many variables at play with this method that can affect a print’s quality. Here are some potential screen printing problems and solutions to ensure your print turns out sharp.
1. Image Has Bled and Ruined the Design
Although screen printing has many names, the actual printing process is always fairly similar. The way the stencil is created can vary depending on the materials used, but it’s essential to prepare it correctly.
Different stencilling techniques include:
- Using masking tape or vinyl to cover the desired areas of the screen.
- Painting the stencil onto the mesh using 'screen blockers' such as glue.
- Using a light-sensitive emulsion to create a stencil which is then developed.
Designs made using the screen printing technique can use several shades of inks. In the case of multicoloured items, the colours must be applied in individual layers, using separate stencils for each ink. In each scenario, there’s the potential for bleeding - meaning your intricate design could just be an inky blur.
Solution
Squeegees. These commonly overlooked tools can greatly impact print quality. A sharp squeegee edge is preferred, without any nicks that might get caught on the fabric. This helps to shear off the ink better, allowing it to easily release from the screen.
If the edge is worn or rounded, it makes it harder for the ink to clear the screen, making the print feel rough to the touch. To produce a crisp screen print without bleeding, the screen needs to be able to snap upward, shearing the ink as the squeegee passes.
2. Loss of Detail
Screen printing is best used for high numbers of repeat items, but does take significantly longer than its digital counterparts. So when your intricate stencil details aren’t coming through, it can be bothersome for that run.
While the complexity of the process does mean there's a limit to the number of colours the printer can use, it’s rather cost-effective for large orders and does allow for more intense colouring than you can achieve with other methods. However, there are a couple of reasons why you might be losing important details in the final print.
Solution
A screen tension meter can be a very valuable tool to keep print quality sharp. Screens loosen over time due to the constant pressure of the squeegee. When screen tension becomes too low, the mesh can shift during printing, causing the edges of the print to blur.
Printers can avoid this problem by checking their screens before every printing job with a tension meter. Screens which have slack tension should be retensioned or replaced accordingly to ensure print continues to wow.
However, if spectcaular printing is something you want every single time without fail, it might be that screenprinting just isn't for you. It’s imperfect and unpredictable nature can’t always guarantee a high-quality print. It’s a contrast with the consistency LED UV print provides. This solution can really up your print game, offering vivid colour, HD finish and a quick drying time for print to steal the show.
3. Ink Viscosity Is Off
If the ink consistency is off, it can create less than desirable results for your screen printing project. To understand the best viscosity, this is how screen printers often refer to inks - either short or long.
- A short ink tends to drop in a blob - like a spoonful of gravy.
- A long ink is stringy like syrup.
All screen printing inks will seem short when compared to the traditional inks used in other types of printing. Screen printing inks evolved not from ink, but from sign paints and still retain some of those paint-like qualities.
Generally, a short ink is ideal for screen printing. If you need a more eco-friendly alternative, water-based ink is best.
Solution
Additives may need to be mixed into the ink to thin it out or to tailor it to the project, such as adding a low-bleed additive (sparingly). These additives can sometimes thin the ink beyond the ideal viscosity, allowing it to bleed beyond the bounds of a stencil during printing.
A rheometer will help to identify the right consistency. Ink should be thoroughly mixed, aiming for a paste-like viscosity to create vibrant printed materials.
Screen printing is great for fabric and abstract posters and logos, but doesn’t translate the finer details as well as other printing techniques available. Litho, LED UV, Digital, Laser… the list goes on. You can explore all the different techniques in our guide and take your print to the next level by finding which method is right for your job.
Explore Other Printing Techniques
Books, leaflets, posters, cards, signs, brochures, prospectuses and clothes - all of these items rely on print to convey their message.
Some people claim that the digital world has destroyed the print industry, but that’s just not true.
It’s still as relevant as ever in your marketing strategy. That’s why we created a guide to all the printing techniques you can utilise for your business. Click below to get access.
