Answer: Muskmelon or canteloupe have a netted skin. Look for the skin color inside the netting to change from green to a cream color. The "belly button" where the vine attaches to the canteloupe is another indicator. It will begin to detach. When it is 3/4 detached (growers call this 3/4 slip stage) you can pick the fruit. This can be a bit tricky if you haven't observed the process of "slipping" as it develops before. Also, varieties differ in their tendency to "slip". Finally, I find that smell is a good test. As a canteloupe ripens it gets that wonderful fragrance detectable even on the outside.
Varieties differ somewhat in size and appearance, so you may need to give it your best guess and pick one. Then you will have an idea whether you would need to allow it to ripen more or not.
Enjoy those cantaloupes!
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