Tech Tip: How Humidity Affects DTG and Inkjet Printing

printing-humidity-hygrometerDid you know if the humidity in your printing room isn’t within a certain range, you could be causing irreversible damage to your printers and media? Something so easy to overlook can be the source of lost production time, money, and energy. In this article, we’ll discuss how humidity affects Direct to Garment and inkjet printers, how to monitor it, what the ideal humidity range is, and how to control it.

Let’s get started with the basics.

What is humidity?

To put it simply, humidity is “the amount of moisture in the air.” (source)

It’s what makes New York smell in the summer and has allowed us to have tonal language.

When we talk about humidity as it relates to direct to garment and inkjet printers, we are referring to relative humidity.

Relative humidity is “The ratio of the actual amount of water vapor in a given volume of air to the amount which could be present if the air were saturated at the same temperature.” (source)

Here’s an example: if the relative humidity in your printing room is 60%, the air is holding 60% of the water vapor it can hold, depending on the temperature. The higher the temperature, the more water vapor the air can hold, but the lower the relative humidity will be and vice versa.

Now that we have a basic understanding of humidity, you probably want to know…

How Does Relative Humidity Affect Printing?

Great question. If the air is too dry in your printing environment, the ink in your printer will dry out, leading to clogged nozzles in the printhead and your paper will curl. You might have a space heater in your location if it’s cold or it’s during the winter. Or you could be in a geographic location with low humidity.

If the air is too moist, the ink on your media won’t be able to dry.

Nothing is more frustrating than spending hours troubleshooting a seemingly simple printer problem, let alone waiting days to get a new printhead, only to keep experiencing clogged nozzles or damaged media.

You need a tool to assess and monitor your print location’s humidity and temperature.

Use a Hygrometer to Measure Humidity and Ambient Temperature

We recommend buying a relatively inexpensive tool called a hygrometer. A hygrometer “is an instrument used for measuring the moisture content in the atmosphere.” (source)

Hygrometers allow you to monitor your production room’s humidity and temperature on an ongoing basis. We recommend placing one in your printing room and monitoring it daily. You could save hours (or even days) of lost productivity and frustration.

Now that you know how to measure humidity and temperature, you need to make sure to operate within a certain range.

The Ideal Relative Humidity Range for DTG and Inkjet Printing

For direct to garment and inkjet printing, the humidity range you want to target is 40%-60% RH. As mentioned above, this will help prevent the inks from drying, preventing nozzle clogs in your printhead and warping your media. You also want the ambient temperature between roughly 70-90 degrees.

During Wintertime or if you are in a dry geographical region, you will need to control the humidity around your printer.

How To Control Humidity

So now you know what relative humidity is, its relationship with temperature, how to measure it with a hygrometer, and the ideal range for printing. But what if your printing environment’s humidity is too high or too low? How do you adjust your relative humidity?

To increase relative humidity, you need a non-misting, evaporative humidifier. To decrease relative humidity, you need a dehumidifier. These devices range from commercial to home use to custom.

The bottom line: you need to be proactive and monitor the relative humidity and temperature in your printing space on an ongoing basis to prevent damage to your printers and media.