Stock Pot comes with a well fitted lid. Inspect it round and round and you’ll notice a very negligible to no gap at all. It is good for keeping the contents safe from insect and other unwanted things. In fact, I have never seen ants passing through.
However, it has one big flaw. It never has locking mechanism. Yes. It is a good fit but the only thing holding it on stock pot rim is gravity. It is likely to go out of proper position when held in angle and fall over when swiped accidentally.
In my case, I use stainless steel stock pots to temporary store freshly ground cocoa liquor. Keeping them until hardened or until ready for molding the next day. I am very cautious in handling and keeping them. Trying my best not to accidentally toss the cover off. However, no matter how careful I am, and no matter how many times I told my co-worker to be careful, I often find a container with deranged lid. A free entrance to all nearby contaminants.
With a bit of creativity, 3d printer, crude 3d software skills and several trials and errors, I came up with a 3d printed stock pot lid lock composing of 3 printed parts and screw and nut set.
Now every time I put contents on stock pot for temporary storage, I am securing the lid with at least two locks.