Skip to content

Interval Test

The Interval Test provides a quick way to determine the optimal Line Interval for a given combination of machine, material, and focal length.

The Interval Test pattern is made up of a user-specified number of sample squares, each engraved at a different Line Interval. Text is engraved next to each square to indicate the Line Interval it was engraved at.

Line Interval is the distance between scan lines when raster engraving, making it one of the key settings determining the quality of engravings on Image and Fill Layers. It is mathematically tied to the Lines per Inch value, and both are set in the Cut Settings Editor

Unlike in traditional print media, a higher density of scan lines (lower interval) typically doesn't produce a higher quality image when laser-engraving — an optimal value must be found.

If Line Interval is set too low, the engraving time is vastly increased, and the images appear dark and muddy.

If the Line Interval is set too high, more power is required to achieve the same depth and darkness, and gaps may appear between the lines. Stepping may also appear on curved edges.

Using the Line Interval Test

Preparation

Place a scrap piece of the material to be tested into the laser, and focus the laser as per your manufacturer's instructions.

The location of the test on your material is determined by the Start From mode and the Job Origin that you select before opening the Interval Test. If you select Absolute Coords, the test will be centered on your laser's bed. Current Position and User Origin work exactly as they do for all other output. See Coordinates and Job Origin for more information on these settings.

Interval Test Setup Window

Open the Interval Test by navigating to Laser Tools → Interval Test, and adjust the settings:

  • settings Speed sets the maximum speed the laser head will travel. The Material Test can help you find the optimal speed.
  • Power sets the maximum power output the laser source should deliver. The Material Test can help you find the optimal power.
  • Steps determines the number of sample squares to make. Reducing this will reduce the material needed, but will also result in larger differences between each test square.
  • Min Interval determines the minimum distance between lines to test (try 0.08mm as a start).
  • Max Interval determines the maximum distance between lines to test (try 0.16mm as a start).
  • Size sets the size of each sample square. Reducing this will reduce the material required, but may make the results harder to read.
  • Select Simple Fill to created sample squares with a solid black fill.

  • Select Dithered Image to create sample squares that are a gradient from black to white. These are often easier to read and provide more information to those seeking to engrave images.

  • Preview shows a preview of the Interval Test pattern, as it will output to your laser.

  • Frame commands your laser to frame the area the Interval Test pattern will be output to in your laser's work area.

  • Save saves the test pattern in the appropriate file format for your type of laser.

  • Start commands your laser to begin engraving the Interval Test pattern.

  • Press OK to save your Interval Test settings — saved settings will be present when you open the Interval Test later.

  • Press Cancel to discard any changes you've made to the Interval Test settings — settings will revert to previously saved settings when you open the Interval Test later.

Interpreting Results

Results are best observed under good lighting and with magnification, if available. Look for the sample square where the scan lines touch without overlapping.

Adjust your Line Interval setting in the Cut Settings Editor, and save your settings to the Material Library for future use.

For more help using LightBurn, please visit our forum to talk with LightBurn staff and users, or email support.