I'm not altering any mason jars, but I have made a card using a mason jar stamp to fill with little teeny punched hearts. That's the extent of my contact with mason jars (unless they're full of green beans from relatives over in North Carolina!).
I would suspect the OP is talking about the mason jar stamps and diecuts that are coming out...you stamp the mason jar or cut one and "fill" it with other stamped images on your page....
I've started seeing them (as an image for scrapbooking) all over the place!
Some examples below....Lawn Fawn also does a couple different Mason Jar stamps but they don't sell them here....
I don't get it really....am not a fan of the mason jar image...other than a real one to keep my buttons in...
Not because it's a "trend" but I will at some point use Mason jars because I'm doing a mini-album about my boys' love of our garden and how they helped with it this summer...the Jillibean garden collection forced me to do it!
I like the trend. I have dies to put through my Cuttlebug ( I think they are in my Spellbinders box) and more than one mason jar stamp. I haven't embellished any REAL mason jars but I would be delighted if I got one for a gift. I have some of my buttons in various jars that I think are attractive or vintage. I like the jars that are old and have the wire "clamp type" closures and the glass lid.
Using mason jars images/stamps in scrapbooking is SO OLD it's new again. I remember searching for mason jars stamps on evilbay at least 10 years ago.
You could get the jar & lid stamps and then various things to go inside like hand candy, candy corn, M&Ms, lightning bugs, flowers with long stems, etc.
Ive used them for a long time, anywhere I thought I needed one, a garden LO, a vintage LO.....and IRL I use them for crafts (table centerpieces), glittery votive holders, and of course to hold anything and everything.
This winter I had BF alter our light fixture in the bathroom to fit mason jars instead of the boring regular globes it came with. And for our counrty themed and located home....it was PERFECT!