Margareta Fuchs and Everson Scheurich of DTG Merch explain how to wash test your DTG prints

Everson Scheurich and Margareta Fuchs of DTG Merch

Flaking inks and fading colours are a nightmare for any print provider, but especially for DTG printers. The good news is that this is often preventable by simply fine-tuning your process, and a simple wash test is an easy way to keep an eye on your output. What’s more, wash testing not only can help you to avoid rejects, it is also an excellent tool for helping you to adjust the settings in the print process to get higher quality results. 

The wash test outlined below doesn’t resemble any of the numerous official wash test standards, but it will give you many valuable insights into the process.

What influences washability?

There are numerous external and internal factors that can influence washability:

The garments Washfastness can vary between different types of garments. T-shirts may have different fabrication, thickness and surface characteristics, all of which can influence washability.

Inks There can be huge differences between inks and all of them need to be cured within the proper parameters.

The process The typical DTG process consists of three steps: pre-treatment, printing and curing.

Equipment The type of equipment you use, along with whether you spray too much or too little pre-treatment, can have a huge effect on the printed colours as well as the washability of the print. Additionally, all your print settings – especially the amount of ink you lay down – may require you to fine-tune your settings for curing.

Curing This is the final part of the process where you ‘bake’ the ink into the garment. This is usually done in a tunnel dryer, on a heat press or using a combination of both. Selecting the correct temperature and applying heat for the appropriate amount of time is essential for best quality results, otherwise the ink may not adhere to the garment sufficiently.

Washing Another factor that can influence washability is how (and how often) the end user washes their garments.

What equipment do you need to do a wash test?

Check for flaking inks, faded colours and other imperfections

You’ll need a washing machine and a dryer. If you don’t own a dryer, you can also hang dry your garment. If this is the case, wash the garments a few more times before evaluating the results. This is because a dryer exposes your clothes to more wear and tear, which influences the final result (However, If most of your customers are likely to be using a dryer, then it is worth also using a dryer in your testing.) While you can use any image you want for wash testing, we recommend adding some solid blocks of colour to make the results easier to compare. Remember to keep one unwashed, printed T-shirt aside as this will be your control sample.

How to do a wash test

To prepare for the wash test, print your T-shirts and cure them appropriately, guided by the ink and machinery manufacturers’ recommendations, making sure that you document all the settings used during the entire process. Next, sort your garments by colour and temperature, turn them inside out and wash them separately. Try to fill each load with at least 10 T-shirts to simulate a more realistic washing process. In a standardised wash test, you would be required to use special laundry detergent. You don’t need to do that for our test, but you should choose a detergent that doesn’t include any additives that could influence the outcome, such as bleach or optical brighteners.

After the first wash, turn your T-shirt the right way round and have a closer look at the print. It’s a good idea to take pictures of all the samples next to the corresponding control sample between each laundry cycle, and take notes on your control sheet (for example, sample failed after the first wash). If you have a spectrophotometer, you can calculate the colour changes that occur in the solid colour blocks. When all the data is collected, repeat the steps. We recommend doing at least 10 washing cycles to get the most reliable results.

Before the wash test…

… after the wash test

After the wash test

When you’ve finished the wash test, take a close look at the results. Check for flaking inks, faded colours or other imperfections. If everything went well and you have no visible or measured colour differences or imperfections, congratulations! Make sure to establish clear washing instructions and deliver them to your customers with the final product. You should also establish clear process instructions and make sure your team understands and follows them at all times, so you get consistent results. If the test failed, repeat the process and use different settings during the printing process (pre-treatment, printing, and curing). Try to find the best combination of all settings that gives you the most durable output. Also, keep in mind that the settings may change depending on the garment you are using.

Quality control

The last thing any DTG printer wants is for a customer to return an order of T-shirts that washed out. The cost and time involved in reprinting an average size job will far exceed the effort you need to put into doing a wash test. Quality control is vital to your company’s reputation and a simple wash test can help you get the best results every time you print. For more information, download our free ebook, ‘Quality Control for DTG Printing: Wash Tests’.