Are water-based inks suitable for professional screen printing? In our opinion, yes: here we explain which aspects you have to pay particular attention to and how to use them correctly in order to ensure they don’t just look good, but are also long-lasting.
- In this article:
- Why are water-based inks a good choice for screen printing on fabric?
- Which materials can water-based inks be used for printing on?
- Self-curing and non self-curing screenprinting ink
- Self-curing screenprinting ink
- Non self-curing screenprinting ink
- How to improve the wash resistance of fabrics that have been printed with water-based ink
- Final tips on choosing your water-based screen printing ink
Screenprinting is a high-durability printing technique, this is why we often see cotton T-shirts or shopping bags that are still in excellent condition after years of washing. Screen printing on fabric is one of the best printing techniques for ensuring long-term durability. Naturally, however, this is only true if the entire printing process is carried out correctly.
To this end, therefore, the choice of ink is absolutely crucial, and in the following brief guide – a more detailed version of which is provided in the book “Saper Serigrafare” a screen printing manual (currently only available in Italian) written by CPL Fabbrika’s experts – we explain why some fabric screen printing water-based inks are long-lasting and others aren’t.
Why are water-based inks a good choice for screen printing on fabric?
Water-based inks can be used to safely produce professional quality prints, they are also odourless (very important) and easy to clean: they can be cleaned with water, without the need to use any solvents.
Just a quick reminder, which we think could be useful at this point: in screen printing we don’t speak about colours or paints. The appropriate term is ink, which of course come in different colours.
Water-based screen printing inks are perfect for beginners, but they can also be used for high volume print runs where the objective is to achieve excellent print results and a high resistance to washing. For example, Aquatech inks are used by those looking to achieve professional quality print results.
Indeed, it’s incorrect to believe that water-based inks are an unprofessional choice that isn’t suitable for “serious screenprinters”. That’s absolutely not the case.
Which materials can water-based inks be used for printing on?
- Usually, water-based inks are used for screen printing on:
- natural fabrics, such as cotton or linen
- synthetic fabrics, but it’s necessary to check to make sure we know exactly which synthetic fabric we’re talking about
- paper and cardboard, but they can’t be laminated. In this latter case, the question of wash resistance is obviously not applicable.
So how can we make sure that water-based inks deliver a great result and, above all, are resistant to washing? This is a question we get asked very frequently.
Self-curing and non self-curing screenprinting ink
To answer the question above, i.e. how to make fabrics that have been printed on using water-based inks wash resistant, we need to use language that’s slightly more technical and explain a key distinction between different screenprinting inks.
- Water-based inks are divided into two broad categories:
- self-curing inks: these dry and cure, in other words they chemically react with the fabric at temperatures as low as 20 °C.
- non self-curing inks: these adhere to the surface of the material and only start curing when they reach a temperature of 160 °C.
Obviously, therefore, this difference in temperature becomes crucial if we’re looking to obtain long-lasting prints.
Self-curing screenprinting ink
At first glance or even to the touch, the ink may appear to be dry in both cases, but only self-curing inks properly adhere to the surface of the material at room temperature; non self-curing inks, on the other hand, remain more unstable: if they aren’t heated to 160 °C, the necessary chemical process can’t be completed, and therefore the screen-printed graphics and designs can’t perfectly adhere to the fabric.
Self-curing inks are a beginner’s favourite: there’s no need for any additional equipment besides a printing station, there’s no need to dry the printed fabric in an oven or using a heat press. But, despite their convenience and the speed at which you can print, these inks don’t always guarantee resistance to washing.
Non self-curing screenprinting ink
On the other hand, non self-curing inks are used by professionals who have all the necessary equipment to heat the material after carrying out the screen-printing.
These inks, once they’ve been “welded” to the fabric (or “cooked”, in technical jargon), are longer-lasting. However, the downside is that it’s necessary to have the special equipment for heating the fabric to 160 °C after printing.
In any case, even in the perfect temperature conditions, the ink requires 72 hours to harden after printing, therefore cotton should never be washed until at least this amount of time has passed.
How to improve the wash resistance of fabrics that have been printed with water-based ink
If you want to use self-curing water-based inks and you’re looking for a longer-lasting print, you can still heat the print, for example by using an iron. By doing this you’ll reduce the likelihood of any problems and obtain a print that’s more wash resistant.
But an iron can’t be used with non self-curing inks, because it isn’t possible to control the iron’s temperature and, in particular, it isn’t able to reach 160 °C, the temperature required for the ink to adhere to the cotton. In some cases, we would also advise using a catalyst: it’s actually necessary to do so with Modatex professional inks, whilst with the Texprint Amex line it’s only a recommendation.
Having clarified the difference between these two types of screen printing ink, which we can consider to be the two main worlds when it comes to water-based inks, you might be asking yourself: which type of ink am I using? You can understand this by referring to the ink’s datasheet, a document that we suggest you should always request from the manufacturer or distributor when purchasing.
Final tips on choosing your water-based screen printing ink
- So, this is what you need to consider when choosing your water-based screen printing ink:
- Which material are you printing on? As mentioned above, we suggest a water-based ink for cotton or non-laminated paper, whilst for synthetic materials you need to check carefully as to what’s most appropriate.
- Do you have the necessary equipment for heating the ink after printing?
- Remember that water-based inks are divided into two major groups: self-curing (which dry at 20 °C) and non self-curing (which dry at 160 °C): this information can be found in the ink’s datasheet. Choose one or the other depending on the equipment you have available.
- If you decide to go for a self-curing ink, you can improve its wash resistance by using an iron, but you should never use an iron with non self-curing inks.
Here you can find all the water-based screenprinting inks
that are sold by CPL Fabbrika