Decorating with Colour

23 March 2020

In design and decorating, is there anything more powerful than colour? Colour can set a mood – green is calming, red exhilarating and black can be anything from ominous to chic.

PVC and Polypropylene colours are available in just about every colour and are a great place to start your designs.  With a coloured stock, amazing finishes can be achieved with relatively inexpensive 1 or 2 colour print techniques.

Now imagine what can be created if you print with the full colour spectrum?  The full rainbow is at our disposal when we choose a Full Colour Process print.

Full colour, or 4 colour print is a process that uses the 4 basic colours (Cyan, Magenta, Yellow & Black – CMYK) mixed in various proportions to achieve photographic quality images.  Anyone that’s used a modern desktop inkjet or laser printer has used a version of this technique.

When using CMYK colours to print onto plastic things become a little tricker.

We have 3 main ways to print onto plastic – each with its advantages and limitations.

Offset Printing

Offset printing uses a specially designed rubber blanket to transfer inks to the substrate, and unlike the photocopier / laser printer which applies all colours at once, the offset machines apply each of the CMYK colours individually, one after the other.

The very large machinery often has additional ‘decks’ so that pre-printing treatments, PMS colour matches and clear varnish finishes can all be printed in-line.  So, even though the materials are being printed one colour at a time – the plain stock goes in one end, and the complete print comes out the other.

The process is extremely efficient and allows for high levels of detail to be achieved in the designs, with rapid print speeds.

Offset printing is however the most expensive form of printing onto plastics, and is therefore generally only suited to large runs so that set ups and run up costs are amortized over a greater number of finished products.   For ring binders or satchels, we would recommend jobs around 1000 items as a good starting place.

Digital Printing

Digital Printing uses a similar process to a laser printer.  Rather than inks like Offset Printing, Digital Printing uses cartridges similar to copier toner.

There is no rubber mat as in Offset Printing either – the images are formatted on the computer and printed directly onto the substrate.  For this reason, digital printing allows great flexibility with design, and the ability to print individualised items with variable data…..think barcodes and ID tags, where every image has something different about it.

Digital Printing is extremely common and cost effective when printing onto paper, but has a higher cost per page than Offset Printing when printing on to plastics.   Therefore, Digital printing is an ideal process to use when quantities are very small, or changeable.  As quantities increase – we may recommend using screen printing to maintain cost effectiveness.

Screen Printing

Screen printing uses a mesh based stencil to apply ink onto a substrate such as t-shirts, posters, stickers, vinyl, wood or other materials.

Screen printing in an ideal decoration technique for PVC and Polypropylene, and offers vibrant colours including fluro and metallic colours.

With screen printing, colours are applied one at a time, and require drying time in between colours.  The process is more laborious and potentially more time consuming than other methods – but is perfect for a design using only 1 or 2 colours.

Screen printing uses inks mixed using the Pantone Matching System (PMS), so specific corporate colours are an easy match.  The PMS system even has colours in its rainbow that cannot be achieved using the CMYK print processes.

As each colour is laid down individually, screen printing also allows us to increase the vibrancy and solidity of colours by either printing white underneath, or doing 2 or more passes of the same colour.

Can you use CMYK for screen printing?  Yes – you can.  However, the finish may appear a little dotty compared to CMYK print by offset or digital print processes.

So which print process is the best for you?

In the end, it will be a balancing act based on the quantity of products required, and the message you’re sending with this product.  Is it a use once item?  If so, maybe photographic quality isn’t warranted.  Is it your Corporate Product Catalogue – maybe one or 2 colours in your logo will get the job done.

Plastics Australia have been decorating with these techniques for over 60 years, covering a wide range of products, uses and audiences, and we’d love to help you too.