Thanks, man!! That's neat! How does it ruin the calibration weight?
Just oil from your hands adds mass to the weight. Sure, 1 or 2 times will probably make no difference for your balance at the range and precision. Regardless, only using gloves or a lint-free cloth is always the best practice.
But, at work, I have a $12k analytical balance! It is the nicest balance I have ever used, reliably measures to 1/10,000 of a gram, and worth every penny of that $12k price tag. When you have instruments of this quality, if you touch a calibration weight 1 time with your bare hands, you just completely ruined that calibration weight! Even worse, if you don't realize the error, you may produce poor data quality, and that gets really expensive really quickly in my field.
Needless to say....I have a set of calibration weights under lock and key.