The drain in my kitchen sink was very annoying. If I left too many things in the sink (as I am wont to do), invariably something would push the strainer down and make it close off the drain. Water amasses, and my delicate hands are forced to plunge in and resolve the issue.

I rarely ever need to stop the drain, so I made this.

It is 82mm in diameter and 6mm thick. Scale it to fit your drain. I wouldn't make it too tight of a fit either. I made mine a little smaller than the drain, so I can pull it out without a handle.

I'd also recommend not using a raft, unless your settings are really dialed in. All of the holes make removing a stuck raft tedious.