Exposure Calculator Screen Printing

by
DC
Fact-checked and Reviewed by: David Chen, Master Printer
Senior Consultant at Screen Print Tech Solutions

Adjusting your exposure unit distance or trying a new emulsion? Use our exposure calculator screen printing tool to calculate precise new exposure times using the Inverse Square Law of light.

Exposure Calculator Screen Printing

Enter any 3 variables to calculate the 4th.

Target Exposure Time 0.00

Step-by-Step Logic:
Calculate to see steps.

Exposure Calculator Screen Printing Formula

New Time = Current Time × (New Distance / Current Distance)²

This calculation is based on the Inverse Square Law, which states that the intensity of light is inversely proportional to the square of the distance from the source.

Source: Anthem Printing Exposure Standards

Variables:

  • Current Exposure Time: The duration in seconds that currently produces a perfect “Step 7” on a calculator.
  • Current Distance: The height of your light source from the glass/screen.
  • New Distance: The target height you want to move your light to (e.g., to cover a larger screen).
  • New Exposure Time: The resulting time needed to maintain the same exposure level at the new distance.

Related Calculators:

What is Exposure Calculator Screen Printing?

Exposure is the most critical step in screen printing. It involves using UV light to harden emulsion on a screen mesh. If you move your light source further away to accommodate a larger frame, the light intensity drops significantly.

An exposure calculator screen printing tool helps you skip the guesswork and manual test strips when you change your setup. By understanding the math of light physics, you can ensure your stencils are always crisp, durable, and easy to wash out.

How to Calculate Exposure Calculator Screen Printing (Example):

  1. Start with your known good exposure: 60 seconds at 12 inches.
  2. Determine your new height: 24 inches.
  3. Divide new distance by old distance: 24 / 12 = 2.
  4. Square the result: 2² = 4.
  5. Multiply original time by the factor: 60s × 4 = 240 seconds (4 minutes).

Frequently Asked Questions (FAQ)

Does this work for LED and Metal Halide? Yes, the Inverse Square Law applies to all point-source light units used in screen printing.

Why did my screen wash out even with the calculated time? Ensure your emulsion is fresh and your distance measurement is taken from the light bulb/source to the screen glass.

What is a Step Wedge Test? It is a physical strip used to find your “baseline” time before using this calculator for adjustments.

Is distance measured in inches or cm? You can use either, as long as you are consistent for both current and new distance variables.

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