The Screen Printing Darkroom

How many times have I been in print shops and especially in the screen-printing darkroom? That’s where you first see the level of a screen print department.

Screen Printing Darkroom

I have seen beautiful machines in the front, expensive screenprinting machines, and just looking into their darkroom was just a disaster…

Here is my most recent example of a darkroom that is a copy of too many of the workshops that I visit.

Screen Printing Darkroom Workshop
Screen Printing Darkroom bad example, it been so dark inside, they even open the window, sunhine enters!?

A darkroom does not mean that you have to work in the dark. You don’t have to paint the walls black; it’s not a meeting place for people who are tired and want to take a nap or play hide-and-seek.

The Darkroom is the most important Room in your workshop.

The dark room is the most important room in your print shop.

This is where you start to make the frames that will last you through the production process. This is where you get the best out of your artwork. If the frames are well made, you will have the pleasure of printing smart and beautiful. And it all depends on whether your production runs smoothly or whether you have breakdowns on your screen printing press and production nightmares. 

Some basics:

The Darkroom is a climate-controlled area with a humidity level of 30-40% (MAX 50%)! The first tool you need in this room is a hygrometer.

It’s an inexpensive tool that you can find in many DIY stores. The reason you need one is that your emulsion needs to be dry. More importantly, because the emulsion acts like a sponge when it is not yet exposed and absorbs water from the air, you better make sure that your humidity stays below 40%. A hydrometer is really just a quick indicator to show you what is going on.

If you come from an area where the humidity is low all year round, that’s great, as you won’t need the following tools to control the humidity level, on the contrary, you’ll save some money.


To control the Humidity Level in your Darkroom

In order to maintain a constant humidity level in the circulating air, an air conditioner or dehumidifier is usually used, the size of which depends on the size of the room in cubic metres (m3).

Ask a specialist which is the right unit for your room. You would also need to run these units 24 hours a day, as the coated screen printing frames you are preparing will not be affected even overnight.

Not to mention, if you are using an air conditioner, use the “dry” moisture removal settings, not “cold”. We don’t need a cold room, we need a dry room, and with these settings you will save a lot of money on your electricity bill and help the environment.

Keep the DarkRoom closed! How often do I see companies install an air conditioner and then leave the entrance door open all the time (see picture above, screen printing company). This makes no sense. Close the doors and windows!

Not only do you want low humidity in your darkroom, you also want it to be dust free. Wet emulsion seems to act as a magnet for dusk. Use an aspirator to remove the dusk, but please do not use a water aspirator, use a dry one. I have seen people invest in a dehumidifier and then use a water aspirator to remove the dusk =) THERE IS NO WATER IN THE DARKROOM.

Light up the Darkroom

First, light up our darkroom! Paint the walls white and install a yellow safety light with very low or better non-UV radiation. First and foremost, you need to enlightenthe right light = much better working area, no exposure of the frame before development the room well. White walls don’t produce UV, so you don’t need dark painted walls, so paint them white!

First light up the darkroom! Paint the walls white, install a yellow safelight with very low or better non-UV Light radiation. Above all, you need to light the room well. White walls don’t produce UV Light, so you don’t need dark painted walls, so paint them white!

Darkroom safety comes with proper lighting!

To dry your Photo Emulsion

You would also need a heater in your drying cabinet, which is usually used in a box where you dry your screens. Don’t overheat your frames, 30-40C should be more than enough. But don’t let the dust in, it’s your enemy.

This will help you to create better long-lasting frames, because:

  • No dust in the emulsion = fewer pinholes
  • The right humidity = better frame development, more durable emulsion, easier recovery
  • The right light = much better working area, no light sensitive emulsion  exposure of the frame before development

Screen Print Darkroom Summary

  • Emulsion needs a humidity level of 30-40%
  • Darkroom is a climate-controlled area
  • A Darkroom is a Dusk Free Zone
  • Light is essential, but without UV radiation
  • A must-have, basic tool is a Hydrometer
  • Proffesional Screen printer are very concern about there darkroom.

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As a German resident of Mauritius with a loving wife and two children, I bring more than 35+ years of experience in the screen printing industry. Although English is not my first language, I use advanced artificial intelligence to optimize the clarity of the content, and re-edit so that the factual content is accurately reflected to my knowledge. About this Website and more about Stefan Mertes

Companies i have screen printed for

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