For years, my mother refused to go rafting, despite the fact that my dad, my brother, and I took at least a trip a year as we grew up. Finally, when both my brother and I became guides, she caved and, though apprehensive right up until we finally pushed off from the put-in beach and on edge for a good part of the trip, ended up LOVING IT. Ever since, it's all she can talk about. She proudly tells everyone she's a river rafter, even people she passes on the street, telemarketers, or Verizon support representatives.

So as Mother's Day 2013 approached during my Artist-in-Residency, I figured I had to make her something, and why not have it be rafting-themed? After considering a number of other options, I settled on designing a simple license plate frame with appropriate, slightly ironic text. Why this? My mom loves her car and even though she doesn't drive a huge amount, it's enough to make a auto accessory a reasonable idea. She didn't have a license plate frame before, so there was an opportunity too.

Overall, a super simple but fun project with a great result!

Step 1: Supplies

1. ~ 7 x 13" acrylic (bigger if you want more of a buffer so your laser doesn't go off your piece). Nice to leave the protective paper on the acrylic during cutting - helps keep the surfaces nice and as randofo pointed out, it would allow you to paint the background (etched part) a different color if you please, and THEN remove the paper. I chose red because it's one of my mom's favorite colors and it would go well with her black car.
2. Laser cutter
3. Computer with Illustrator or similar

Step 2: Design and Textify

I stayed pretty simple because the text was the main attraction. Lots of options for making cool designs though! Before you design, know the following dimensions. (I've also uploaded a couple of files I found during a quick google image search).

- US license plate dimensions: 6 x 12"
- example frame outside dimensions: 6.25 x 12.5"
- bolt hole size: 0.25"
- horizontal distance between bolts (center-center): 7"
- vertical distance between bolts (center-center): 4.75"
- height of license plate letters (CA): 2 5/8" for painted blue part, ~3" for entire extruded size

Other things to keep in mind:
- where are the registration stickers? do you want to design around them?
- what are the dimensions of the license plate indentation on the back of the car/trunk/bumper? how big and crazy can you get with the design without it interfering with the body panels?
- is there curvature of the body panel inside the license plate indentation?

The Illustrator file I made is here as well - feel free to start with that and edit from there.

MomLicensePlateFrame.ai
Download

Step 3: Etch/cut

Before you cut the acrylic, definitely throw a piece of cardboard in the laser cutter and make sure everything gets etched and cut as expected. The last thing you want to do is mess up a piece of acrylic because of lack of prep.

When you've made sure the laser's path is correct, toss the acrylic in and let 'er rip!

I did two passes for the etching parts to get a little more depth than one pass would do; as long as the material doesn't move at all you can do as many passes as you want to achieve whatever depth is desired.

Notes:
- lines (specifically hairline lines) get cut by the laser
- anything filled in gets etched
- I had some issues with the laser starting to cut around the letters after it etched...realized I had selected it all and turned it all to hairline, so be careful with that

Step 4: Remove Protective Layer

Now you've got a cut-and-etched license plate frame, and it's still covered. Remove the paper carefully - I used my fingernails instead of any sort of tool to minimize the chance of accidentally scratching or denting the acrylic.

Step 5: Prepare License Plate Holder and Attach

Because the text is so important, I chose to not make holes for the bottom two bolts on the license plate holder; instead, I decided to chop off the bolts so the plate and the frame would sit nicely and not rattle. Here are the steps I took:

Cut the bottom two bolts off at the interface with a hack saw
Cut a couple pairs of velcro squares (you only need the softer, female side of the velcro for this step
Apply the female (soft) side of the velcro to where you just removed the bolt extension (this is just padding, to eliminate any chance of rattling
Slide the license plate onto the top bolts
Cut a couple more pairs of velcro squares
Affix the female squares to the license plate as shown
Affix the male squares to the license plate frame you've made
Slide the frame onto the top bolts and press where the velcro was attached

You're done! Now cruise around town and watch all the jealous drivers stare through your rear view mirror...