There are many different graphic software packages and many different laser brands. Each will have their own terminology and steps. This tutorial will cover more specific and advanced design concepts. You will need to translate these steps into your specific application.
Overlapping Objects vs. Punch Outs
Designs that have two objects that seemingly overlap each other can be handled two ways depending on the desired effect. In this example the Blue Arrow will be engraved on the front panel and the Red Box will be engraved on the middle panel.
- Top Example: If you engrave the objects by just overlapping them and then apply the lights with blue on the arrow and red on the box, you will get a purple arrow.
- Bottom Example: If you ‘Punch Out’ or Subtract the arrow from the box on the middle layer, then there is no engraved object directly behind the arrow to mix with, giving you a blue arrow.
Overlapping objects and punch outs can get confusing when you are working with 3 layers.
Tips when using punch-outs:
- The front panel never needs anything punched out.
- The middle panel needs all of the overlapping objects from the front to be punched out.
- The back panel needs all of the overlapping objects from the middle panel and the front panel to be punched out.
Lasers are not known for being friendly with ‘Transitional Gradation’ (meaning a smooth transition from dark to light) in your design.
Often, the laser will produce a ‘banded’ result:
Luckily with Etch Glow Light Displays, if you etch everything with a solid fill then the object will appear to gradate somewhat once the color from the light is applied.
That’s because light is not infinite. As the light travels from the light board to the top, it exits through the engravings ‘using up’ some of its power or lumens along the way.
Depending on the engraved graphic, it might be noticeable and other times not.
Color vs Grayscale
We recommend designing your Etch Glow Light Display in color and then converting it to grayscale (shades of gray) before you send it to the laser.
Converting to Grayscale allows you to have better control over the depth of the engraving because you can see the relative depths before you engrave it.
Shades of Gray
Most lasers control the depth of etching by using the color of the object being engraved. The denser the color, the deeper the engraving. Black will engrave the deepest and light gray the shallowest.
Figure 1: Relative Smooth Transitional Depths - not to scale
Figure 2: Relative Banded Gradation Depths - not to scale
Since we know that lasers are not that friendly to a Transitional Gradation like Figure 1, we recommend using only 5 levels of solid fill gray in all your design objects.
Example: The Police Badge Design has a solid design on the back piece of clear acrylic. How dark you set the fill will create different results when you apply the lights.
For a large shape with a lot of fill you can see an interesting pattern. The lighter etching (light gray) produces a fuller and richer result than the darker etching (black).
That’s because the deeper etching (black) ‘uses up’ more of the light as it travels from the LEDs to the top.
Using the ‘Punch Out’ technique, if your design calls for it, will help smooth out the color blending.
The light isn’t being ‘used up’ in the areas not engraved (punched out), so the light will travel further toward the top of the design
Tip: To get good light coverages on larger objects
- Engrave with a lighter gray
- Use Punch Outs where possible.
Black and Shades of Gray
Something else to consider. Lighter etchings (light gray) will produce a more pixelated result when lasered – meaning the dots will be spread out more. How much will depend on the quality of your laser.
Some lasers allow you to control the dithering (dot pattern) as well as the DPI (dots per inch) or LPI (lines per inch). We have found that increasing these adjustments will have limited impact on the results, however, they will dramatically decrease the speed of your laser.
Etch Glow Light Displays use lights to illuminate the engraved pixels. When the light hits the pixels, it gives off a slight glow in all directions, filling in any spaces between the pixels with the color of the light.
Tip: Engrave at a lower DPI either through laser settings or by using lighter grays colors in your large fill areas. This will produce the best quality result at the fastest speed.
When to use Black
We’ve established that larger fill objects (backgrounds) should be engraved with lighter grays.
However, many times, you will want to use a dark gray or even black fill in your objects. Especially smaller objects or objects that you want to be well defined with sharp edges and without pixilation.
Text is a great example of when to engrave with Black fill:
Mixing Black and Gray
There are also times when you might mix shades of gray with black in your designs.
In the star example we engrave part of the star with a light gray fill and part with a black fill. This is how to create shadows or highlights in an object. Both the light gray and black are engraved on the same panel:
What if Black is one of the Colors in your design?
Since Black is not a color available in lights, how do you make an object black when the lights are turned on?
Your Etch Glow kit comes with Black Cardstock material to make a Backer. If you punch out the object that is to be black from your design, then it won’t be engraved, and you will see right through to the backer (which is black in this case).
Our kits are packaged with Black Cardstock, however, you can use any color or patterned cardstock (or other material) to get different results.
The patented Etch Glow Light Board uses LED lights that have a spread pattern of about 22 degrees.
5 LED lights on each row provides coverage for the entire acrylic panel.
Light Path with Cutlines
When designing your own shapes to be cutout, avoid any gaps or holes that won’t get any light.
The light needs a continuous path in the clear acrylic to reach the entire design.
The Spotlight Effect
Placing large solid objects too close to the lights will cause a spotlight effect.
All our designs are setup for engraving on the front side of the material. Sometimes you may want to engrave on the backside of the clear acrylic panels. This leaves a smooth front, and it creates a bit more depth to the finished product.
If you want to try Backside Engraving, remember to flip the image before you separate it for engraving individual panels.
Remember to flip the cutout lines as well. In this example the cutlines are symmetrical so it wouldn’t matter, but it is a good practice to flip everything.