Photoshop, that is! (You can read all about my learning experience with Photoshop here. )
My sons are 17 & 18.... and they still do not put their dishes in the dishwasher unless I tell them to. According to them, it's because they don't know if the dishes in the dishwasher are clean or dirty. Of course I'm standing right there so they could ASK, but it's much easier, I guess, to stack them on the counter NEXT to the dishwasher and wait for the "dish fairy" to take care of them. I guess I can be thankful that they at least scrape and rinse them for me!
This is an easy project that takes no time at all to make. You'll need some hardboard (or lightweight, thin wood of some type), Mod Podge to adhere the cardstock sign to the board (or watered white glue works just as well) and a couple of magnets (you can re-purpose old fridge magnets, if you have them).
After you've printed out your image (use cardstock if you have it) just mount it to your pre-cut wood with ModPodge or glue, smooth it out (I use the side of a cut paint stick) and coat the top... this will help with moisture when the "dry" cycle is running.
If I have it, I'll use a spray can of clear coat to spray the finish on (versus ModPodge). I just find it easier and quicker.... and I don't get the brush marks. However, either one works fine... use what you have.
The graphic is free and can be downloaded by clicking on the image above.
Now we'll see how long it takes for them to a) notice the sign and b) to see if it makes a difference!