I was wondering how teams print designs on their Plexiglas.
Sharpies and a lot of time? Maybe some spray paint to speed up the process 
Probably just CNC vinyl, like from a Cricut machine or one of the other cutters. That’s how I would do it at least, really easy to cut mirrored and apply to the back side.
Is there an easier way, we don’t have access to a CNC machine in our high school.
Ok, what we do is we just print it out on a peice of paper, then tape it to the other side of the plexi, if you do it right no one can tell the difference
Oh wow, that is exactly what I was thinking, but I assumed there was a better way.
What we did is that we printed multiple pieces of paper then we connect them to form one giant image for your plexiglass. its actually pretty simple, you just split an image into 3-5 equal slices, put each on their own slide or however you want to do it ,scale them individually to the size of a paper, then print them, cut them, then tape them together.
Lol, (almost) won worlds and no wear was shown, so i think its the best/easiest way
You can also laminate a piece of paper. That’s my strategy.
We’ve been using Staples Print Services. They print poster size (12" x18" or 18"x24" if you really need it), and they offer laminating too. It’s very convenient and gets a high quality result.
My wife has vinyl cutters for her business that I occasionally use with teams to cut their graphics. You can check with sign shops in your area - many have that capability. There are also Custom Vinyl Cutting services on the web. Some sites have an application online where you can design a 12"x 12" image for about $20. They will ship it to you on backing paper. You carefully place it on your clear plastic and press down. Just know that it is a one time application so plan carefully and take your time.
The image below shows clear plastic that we cut to match a Vex plate. The vinyl was printed backward, placed on the back of the plastic and sandwiched between the plastic and the plate.
You could always try this: http://www.instructables.com/id/Transfer-Photos-onto-Plexiglass/
Probably not as high quality as getting it directly printed on the Plexiglass, but much cheaper.
We just put our design on auto cad and cut vinyl using the vinyl cutter. Then just put it on the plexi glass.