Light My Fire Pack-up-Cup Owner Review by Bob Dorenfeld June 4, 2015 Tester Bio Name: Bob Dorenfeld I'm an active hiker, snowshoer, skier, and of course backpacker.  Home base is the Southern Colorado Rockies, ranging from alpine tundra to piñon-juniper scrub and desert at lower altitudes.  Many of my backpack trips are two or three nights (sometimes longer), and I usually shoulder about 30 lb (14 kg).  My style is lightweight but not at the expense of enjoyment, comfort or safety - basic survival gear plus extras like a camera and air mattress make my trips safer and more pleasurable. Email: geartest(at)sageandspruce(dot)net Age: 57 Location: Central Colorado, USA Gender: M Height: 5' 6" (1.68 m) Weight: 142 lb (64 kg) Product Overview   Manufacturer:  Light My Fire  Website:  www.lightmyfire.com MSRP:    N/A Country of Origin:  Sweden Materials:  Thermoplastic elastomer (TPE) and Polypropylene (PP) Stated Weight:  54 g (2 oz) Measured Weight:  54 g (2 oz) Measured Size:  100 mm high x 75 mm top x 45 mm bottom (4 in x 3 in x 1.75 in) Capacity:  260 ml (8.8 fl oz) Color Reviewed:  Blue   Light My Fire's Pack-up-Cup is a very lightweight, compact drinking mug with a hinged lid.  The cup collapses to about half-size for travel, and can hold both hot and cold liquids.  The slip-resistant TPE bottom half is soft and flexible for holding, while the rigid PP top half and lid keeps the cup's shape and contains drinking and air vents.  The Pack-up-Cup comes in six top-half colors (all with dark gray bottom): yellow, magenta, black, blue, green, orange.  According to Light My Fire the cup is free of BPA. Field Performance     I've used my Pack-up-Cup on three backpack trips and several day hikes so far this 2015 season.  I don't need a large mug, nor do I need to eat out of a mug or cup (I use my cooking pot for eating), so this very light cup is perfect for me.  It packs down to about half of its normal size by just pushing the flexible bottom up into the top, where it stays until needed.  To restore the cup, I open the lid and push the bottom out.  The lid flips open on a small hinge molded in one piece with the rim, and it snaps securely into the rim via friction.  There is a small sipping hole at the front of the lid, with a smaller air vent on the opposite side. The cup holds 260 ml, which at just over 8 fl oz is just right for a cup of coffee in the morning, or a cold tea to enjoy after pitching camp.  Since most of my meals take about a cup of water to prepare I can also use the Pack-up-Cup to easily prep dinner or breakfast. I like the soft and flexible TPE because it's easy to grip, and it holds the heat of a hot drink more than long enough for me (about 10 minutes in freezing temperatures).  It's not too hot to hold after pouring boiling water into it, and in fact it makes a great hand-warmer on cold mornings!  There are measuring lines in both ml and fl oz in the inside of the cup, but I find them difficult to read and rarely use them.  The cup is easy to clean: I usually just rinse with water.  Light My Fire says that the cup is dishwasher- and microwave-safe, but I haven't yet put it in into either appliance (couldn't find them on the trail!). There are, however, two aspects of the Pack-up-Cup that I think could use a redesign.  The photo at left shows the slightly bulging bottom, which is enough to make the cup rather unstable - it wants to tip over if not supported.  The other issue is the tapered bottom half, which makes the cup a bit top-heavy.  Although the tapered bottom makes it easy to collapse into the top, I wonder if it's possible to redesign with less of a taper yet allow the TPE to still collapse into the top half.  Nonetheless, I've noticed that with a full cup its weight is enough to press the bottom bulge down; however, at half capacity stability again becomes a problem. Concluding Thoughts     So far I think the Pack-up-Cup is a great addition to my gear.  It's easy to use, packs up very small, and keeps drinks warm for as long as I need.  Although stability is a problem, especially when less than fully filled, I've learned to prop the cup against a tree, branch, or something else to keep it from falling over.  For me that's not a big issue, as the Pack-up-Cup's advantages outweigh this problem.  The cup has been durable to this point, showing no signs of wear. Pros    - very lightweight    - collapsible and easy to store    - keeps drinks warm    - easy to sip (doesn't dribble)    - easy to hold with bare or gloved fingers Cons    - not very stable    - measuring lines and units (on the inside) are very small and hard to read  Reviewed By Bob Dorenfeld Southern Colorado Mountains