Having recently left the last of the kickstand plates somewhere along our route, I bandsawed, belt-sanded, and Forstner-drilled a new set:
The slightly rectangular shape extracted four plates from of a scrap of 3/8 inch plywood, with almost nothing left over. The fourth plate had already found its way into the under-seat bag by the time I thought of a picture.
My can of fluorescent red paint having lost its mojo since the most recent application, these shall remain unpainted forever more; as even forget-me-not red seems to have little effect, that may not matter.
The Smell of Molten Projects in the Morning 
If space allows, maybe the trick is to connect it to a kickstand more permanently.
But I have a more pressing question: how does this relate to Vacuum Fittings? :)
Well, now you know where the sanding dust went!
Not sure how you store them while riding, but maybe a retainer cable or cord clipped to the frame so that you can’t ride off without them getting your attention. Not even remotely related to bikes, but I use a retainer cord on my mower and tractor keys. Some ignition switches are so loose with keys (even when new) that the key can fall out while running and continue to run. Try searching 10 acres for keys … I will say that I constructed a duplicate set from spares and tested a rolling magnet with them in the grass and it picked them up every time. That way I knew I wasn’t wasting my time searching for them using the magnet. I did find them, but it won’t happen again.
The underseat bags have mesh pockets of just the right size. Unfortunately, the bags completely obscure the kickstand, so I must pick up the plates despite my habit of sitting down, knocking the kickstand back with my heel, and riding off. Alas, I probably wouldn’t notice a plate clattering along under the bag until the end of the ride.
Now that I have some history, it seems the two of us lose a half of a plate every year, so we’re good for a while. If the pace picks up, though, I’ll definitely consider a leash… [grin]
http://www.homedepot.com/p/4-in-Square-Blank-Cover-Flat-8752/100542712
What‽‽‽ Spend money? Surely, you jest!
Bonus: I’m whittling away at the woodpile.
Nothin’ wrong with being a cheapskate, you just market it as recycling or better yet up-cycling :)
You can get wood flooring samples about that size for free, but using the wood you already have makes more sense.
There’s a thought: genuine teak kickstand plates! [shudder]