So I have a little experience with this! Last summer I designed, printed, and painted my own plugs. Went through a ton of variants and learned a lot about designing lures and 3d printing.
I designed my plugs with Tinkercad, which is free and easy to use. Its like MS paint for 3d design. Very basic but so is a plug tbh. I printed mostly using glow PLA. My plugs SLAYED! They didnt catch as many fish as say an AP spoon but the size of fish was noticeably larger. My guests released multiple tyees up to 37lbs using my plugs! It was so cool.
PLA prints arent waterproof, and im not sure any kind of entry level 3d printing would be watertight considering the water pressure at depth. For my first iterations I was focused on shape and action of the plug. After testing I noticed that the plugs had small amounts of water inside. I didnt bother to seal them because i was still figuring out shapes and angles etc.
Once I had some designs I liked, I airbrushed them and experimented with a few different topcoat/sealing methods. I was limited with what I could try because I was at the lodge. From the ones I tried, a 2 part epoxy hand-painted on with a small brush worked best, but eventually the salmons teeth won and water would find its way in. At 200ft deep, the water pressure is so much greater than at surface level that it doesnt take much for water to find a way. The 2 part epoxy was durable enough to withstand somewhere between 50-200 fish before springing a leak.
The injection-molded tomic style plugs are certainly more durable, but its a lot of fun to experiment with different designs, and very rewarding when they work!
