When having items laser cut you also have the option of adding laser score lines. By lowering the laser power the beam will cut partially into the paper instead of through it. I use laser scores for all Candyspotting greeting cards; however, they are not appropriate for every job.
- Precision: scores are computer controlled and will be parallel with the edge of the card.
- No additional cost: the scores are fast straight lines
- Time savings: card does not need to be scored afterwards.
- Potential weak point: if the cut is too deep or the card is flexed too many times it may tear. I err on the side of shallow rather than deep scores. I do not recommend laser scores for pocketfolds or other mailers without an external envelope.
- Exposed fibers: when the card is folded the paper fibers will be exposed. Sometimes irregular fiber bumps can be seen and the score won’t look as nice as a pressure score. For troublesome papers I like to smooth over the exposed fold with a bone folder.
- One-sided: for the most accuracy scores can only be all mountain or all valley, not a mix of the two.
It’s surprising when a design that looks great on screen falls apart or looks completely different when laser cut. I hope you can learn from my overflowing “prototype” box by observing a few guidelines.
Print the design on paper.
When working on screen it is easy to lose touch with the scale of a design. Print it out and eliminate or thicken small design elements.
Imagine your design bending in the physical world.
Cardstock is flexible enough that thin or unsupported elements may bend or flop over. Watch for elements that can catch on envelopes or the laser bed.
The image below shows an example. When the design is first cut it looks fine. The second panel shows a weak spot; it is too easy for the design to bend out of shape. In the third panel the design has been improved by adding tiny bridges to the weak spot.
Reduce the total line length.
Think of measuring the length of a coastline. If you drew it by walking the beach adding every detail you would end up with a distance many times greater than if you drew it from a birdseye view. Try smoothing out your lines or offsetting the path to remove excess detail. On an X-Y laser, the distance the laser head travels has a close correlation to the cost.
Shadows will change how your design appears.
Particularly, the contrast on small cut areas with be greatly reduced and lines will appear thicker than on screen. In the image below the small cutouts have lost their high-contrast effectiveness compared to the original art. The thicker the paper the more pronounced this effect becomes.
Check your compound paths & mind the kerf.
Releasing compound paths may reveal problem areas that need to be bridged. Precise designs should use offset paths to account for the kerf of the laser beam.
If lining your card, leave room for adhesive.
If your design has large cut areas, you will likely want to line it with paper to ensure that the writing on the inside of the card doesn’t show on the outside. If you are using glue or a tape gun make sure to leave the width of the tape line plus some slop.
Prepare for higher failure rates with many small cutouts.
The airflow in the system may cause small cutouts to blow onto uncut portions of the design. If the double thickness causes a skipped area then the small blip may be salvaged with an Xacto knife. Alternatively, if both layers are cut and smoke gets trapped you may try gently erasing the smoke.
Consult an expert
I have made hundreds of stationery designs laser ready. Sometimes the art just needs minor adjustments and other times cut & photographed prototypes are necessary. When working to a budget I can make suggestions early in the design phase.
I had the opportunity to etch a MacBook Air for my friends at Panic last week and made a short video to show the process.
For those of you interested in the craft of Scherenschnitte I thought you might enjoy cutting the main layer of Early Bird as a standalone piece.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
Attribution required: “Early Bird” by Sarah Holbrook (http://candyspotting.com)
There is a trade off between speed and quality with x-y laser cutting. This 80# cardstock test shows a slow run on the left and a fast run on the right. To get the best results I run the laser at a slow speed; it ensures very smooth curves and a close representation of the original art.
At a fast speed the laser beam carriage runs with some wobbles. If this loss in accuracy is acceptable for your project please let me know. Depending on the circumstances it may lower the cutting cost 10-50%.
I was delighted to have Carina of Crow & Canary swing by the workshop last week to take some photos for a guest post on Oh So Beautiful Paper. Here’s what it took to prepare the OSBP logo, with calligraphy by Bryn Chernoff, to be cut.
Here is the original logo:
and here is the laser-ready version:
The original logo would cut as several separate pieces (“O” “H” “S” “O” “Beautiful” “P” “aper” and the dot of the “i”), so the first thing I did was tie everything together. I start with a frame that the words will be bridged to:
The straightforward solution to bridge the text is to add a rectangle that intersects each text baseline. Tall portions of the design might flop over when the paper is held upright, so those need to be secured as well.
Unfortunately, this doesn’t fit with the aesthetic of the logo and the long start to the “P” is likely to sag. Instead, I decided to pull everything together with some well placed curves.
Next, all of the black portions of the image are unioned together. The correct line width and color are selected for compatibility with the laser, the path is offset to adjust for the kerf, and a test cut is made.
The test cut revealed a few weak spots so the paths were tweaked and it was ready to go. The video took several takes; I’m a video novice so it took a while to get reasonable depth of field with the low light in the workshop.
Please let me know what topics you’d like to hear more about. I’ve been working on an FAQ for the site that touches on several areas that could be addressed in more detail. Thanks for reading!
Adjusting the “tuning” in the Universal Control Panel (UCP) can make a dramatic difference in the clarity of raster images. For GCC/LaserPro machines this feature is also called tuning. On Epilog it is called “Laser Match.”
Last autumn I added a second laser to my shop. One day I saw a live auction listing and the next I was the slightly nervous and very excited owner of a machine that I’d never seen powered on. The first text tests were barely legible. One of the many steps to refine the output was to adjust the tuning.
The following diagram demonstrates the result we would like to achieve.
When a raster image is sent to the laser the driver splits it into horizontal slices. Each slice represents a pass that the laser head will make in the X direction of travel.
Tuning changes the distance that the X belt moves before the laser begins to pulse in each row. Poor tuning will cause a misalignment of an etched line in the right-to-left direction versus the left-to-right direction.
The fix is fairly straightforward. First, draw a solid, long thin rectangle. Change the raster settings to use the lowest image density (lines per inch). Etch on a material that has very high contrast. Anodized aluminum is fantastic; since I didn’t have any on hand I used a dark black paper that shows a nice mark.
The desired result is for the left and right edges of each line to be flush. The following image shows an example of running this test. The first column shows the original ragged line. Next, I moved the line over, adjusted the tuning, and ran the job again. This is the value I chose; the next two tests use different tuning values and are slightly ragged again.
After fixing the tuning my sample text was still slightly blurry compared to the results from my other laser. The accelerating/decelleration curve didn’t seem as good on the older model. That is; it wasn’t slowing down enough to give a really clean etch. By lowering the speed I finally saw the crisp text that I demand.
If the tuning value you need to use seems unusually high or low you should check the laser’s X belt; it may be too loose.
Check out the blog post over at Sense Labs about the custom thank you cards I cut for them. They requested a video so I tried to shine enough lights on the work area to make it visible. I also had to temporarily defeat the overlock so that I could film the work area directly instead of through the safety door’s glass.
Enclosed lasers such as ULS and Epilog have a safety feature where the beam won’t fire if the doors are open. On my system the front panel shows a blinking red light when the doors are open and a green light when they’re shut. Yesterday the red light kept blinking even when the doors were shut.
Now, this is a very big problem, since it rendered the laser inoperable.
The interlock on ULS systems uses flange mount sensors (Hamlin 59140), two on each door. The sensor is mounted to the cabinet and the actuator to the door. When they touch the circuit completes.
There are at least five possible failure points:
- Sensor plug
- Lead from the plug to the main system
- Connection between sensor and actuator
The easiest route would be to rule out the connection and actuator first, but I didn’t know how to properly use magnets to do this (more on that later). Instead, I started by unplugging the sensors, inspecting them, and plugging them back in. Still no green light.
Permanently defeating the interlock
The next step was to take the sensor out of the equation. With the machine powered down, I unplugged the sensor and wrapped a piece of tinfoil around the two wires of the plug, completing the circuit. I got lucky with the first sensor I tried, and the light was once again green when the laser was powered up. Now that I knew which sensor was acting up and that the lead to the main system was okay, I could temporarily leave the tinfoil in place and figure out how to test the connection to the actuator.
Overriding the interlock with magnets
The standard trick to temporarily override the interlock is to use magnets. Some laser operators use this technique to engrave items longer than their laser bed. The front door is opened and the item projects past it. Some systems have a front and rear door for full pass-through. Safety glasses must be worn if the doors are open!
To allow the laser to fire, position magnets over the two front sensors on the cabinet. The magnet should be placed on one half of the sensor only; it will not work if it covers the entire sensor (this was the mistake I made earlier).
Removing the tinfoil and using the magnet test, I got a green light again, so the sensor was okay.
Now that I knew the problem was either with the connection between the sensor and actuator or actuator itself, I took a closer look with the door closed. There did seem to be a decent gap between the sensor and actuator, but I wasn’t sure if that was the problem. Since this just started occurring I thought it would be strange that the distance was suddenly too great.
Testing the actuator
With a magnet on one sensor, I unscrewed the actuator for the other and placed it directly on top of the sensor. Green light. Pulled it away a bit, still green light, a bit more, flashing red. I screwed the actuator back in on one side only, so that I could push the other side out a bit, making it closer to the sensor. Success!
Now, why did this happen? This problem occurred on my new-to-me laser, which is not yet in production. It’s been moved around quite a lot lately. First for workshop electrical upgrades, then a hardwired exhaust, and most recently to test tubes and try to get the beams aligned. My theory is that all of this moving has caused the front door to shift slightly so that it is closer to one side than the other. The tiny extra distance is too much for the sensor to pick up. I have tried moving the door back to center but no luck.