Waterproof Posters – What Are The Options?
There are lots of reason’s customers need posters that are a bit more resilient to their surroundings. And being waterproof, or liquid proof is a feature that we’re asked for time and time again. For use on petrol forecourts, to busy area’s it is always an advantage not to have to replace your print just because it got damp or something was spilled on it.
Waterproof Poster Printing Methods
With weather likes we have in the UK, it’s no surprise that clients are often looking to make their posters stand up to the elements. Waterproof poster printing can be done by litho printing, silk screen printing or on an inkjet. The trick (if the print is to be on the final outer surface, is not to use water based inks. Okay, so that might sound obvious but it does limit the amount of machines this can be printed on.
Enter Plastic Poster Printing – PVC, Polypropylene and Polyester Posters
For polypropylene posters and PVC posters, the inks must be able to dry on the non pourous surface. The ink will sit on the surface of the plastic and must by dried quickly before it comes into contact with anything else, such as the next poster being piled on top. Around 95% of litho presses in the UK use vegetable oil based inks which do not dry quickly enough, and need a porous surface to soak into. To litho print onto plastics we have to use a UV drying ink, As soon as the ink is applied, the plastic sheet is fed under a high powered UV light that instantly dries the ink and bonds it to the PVC or polypropylene. UV printing is also the method we use for silk screen and digital inkjet print.
Plastic poster printing is what we tend to do for outside shops or petrol forecourts where they are constantly open to the elements of the great British weather.
The other option for digital print is to use a solvent printer, but they’re not very common these days as they are particularly unfriendly to the environment and more expensive to run.
Prior to UV printing, this used to be the best option to protect your posters when getting wet. Encapsulating (sealing) your conventionally printed poster into a transparent cocoon casing gave it a protective shield against any liquid damage.
A much cheaper way of protecting your conventionally printed poster is to gloss laminate the printed sheet. Much like encapsulate, laminating posters is a process of protecting the print using a clear plastic layer. The main differences with laminating are; (a) that you can choose to protect one side or both sides, (b) the film is much thinner so does not affect the rigidity of the poster. The latter makes it easier to roll posters into tubes for transportation. The disadvantage is that laminate does not overlap the edge of the print like encapsulate, so water can still get in and damage from the edge of the print. Laminate is only really suitable to protect against the occasional splash to the face or reverse, but cannot be classed as full water proofing.
Choosing the right process for your waterproof posters
We’d love to help with any waterproof posters you might need for your or your clients. Please use the link below to contact us and discuss your project.Get in touch