It's no secret Mason Jars are great to repurpose to drinking glasses. There's also plenty of ways (including DIY) to make a sealable drinking spout but what hasn't been done (as far as I can find) is "drop protection" for these glass jars. It's not that Mason Jars aren't robust, they can easily take a fall off a low table to a carpeted or even wood/tile floor. But since DIY folks are usually in garages/workshops/etc. with concrete floors, I wanted to come up with a way to protect a jar full of liquid from a reasonable fall (3-4' max) as well as allow putting hot (near boiling) liquid in the jar and protect any surface it is sitting on (as well as any hands gripping it.) Glass jars are the best containers for liquids that might interact with materials (coffee, tea, juices) since the glass neither absorbs nor taints the taste of the drink. Mason Jars thick glass walls provide some insulation but still allow hot drinks to cool.
Adding bumpers is a fairly intuitive process and uses a minimum of 12 5g Sugru packages of any colors. The bumpers could be hand molded - I preferred some kind of mold, in this case, a pop-off plastic bottle top with no internal threads (but an internal lip.)
Step 1: Materials
1. Mason Jar
2. Minimum 12 5g Sugru packets
3. Depending on your tolerance for hand-molding pieces, something to mold bumpers with (I used a pop-off plastic water-bottle cap with no internal threads but an internal lip.)
4. Wax paper can be handy, not really required
5. For an almost completely "spill-proof" drinking mug, a regular Mason Jar canning ring the correct size for the mouth of the Mason Jar and some kind of sealable lid (in this project, the cut-out top of an impermeable Soy milk "cardboard" container resealable-cap lid and the plastic cap it comes with.)
Step 2: Form Bumpers and Place on Jar
Roll the contents of each 5g packet into a ball in between the palms of your hands and then form into a disc shape or press into a disc-shaped mold (the pop-off water-bottle top in this case.) Stick bumpers on the edges of the mason jar at the top and bottom as well as the base to cover all the protruding points on the jar. The bumpers should leave no glass exposed to contact during a fall.
Step 3: Allow Sugru to Dry and Place Optional Finger Grips and Lid
Suguru needs about 12 hours to cure into a flexible, shock-absorbing, but permanently bonded, attachment to the glass jar.
With an optional lid, it is now ready to hold liquids of any temperature (or anything else that would fit in for that matter), protect any surface it is placed on from the temperature of whatever is in it (heat in the case of coffee or tea) and should survive a fall from 3' to 4' onto just about any surface without spilling liquid.