Marmot Plasma 30 (2013)

The Marmot Plasma 30 has a very hefty price tag, but this is nevertheless an outstanding sleeping bag that pulls off something rare: it actually seems better than Marmot says it is. In comparison to the Rab Infinity 300 – with which it shares a similar InsoTect insulation system and Pertex outer – it manages a higher fill power of goose down, includes little touches like popper closures on the neck baffle and zip ties, yet manages to weigh less than its rival. This is impressive in itself, but the surprises don’t stop there. The Marmot Plasma 30 feels a lot warmer than it suggests; the quoted comfort limit figure is -1 deg C (the Rab’s is -2 deg C) but the Marmot bag feels instantly warmer when used side by side with the Infinity. This could be due to the higher fill power or simply a better fit due to my body shape, but the high loft of the bag and the snugger fit overall means I personally would select this one for a slightly colder night out. Either way, there really isn’t much in it – and while this is arguably the better bag, for this reason that price is a big turn-off.  


Weight (with stuffsack) 644g (665g)
Size 215x76cm
Packed size 35x17cm
Outer fabric Pertex Quantum with DWR
Inner fabric Pertex Quantum
Insulation 900+ fill goose down
Construction InsoTect vertical baffle
Lower comfort limit -1 deg C
Extreme temp rating -14.4 deg C



The Marmot Plasma 30 is an excellent bag – arguably the best here – though not sufficiently so to justify that price tag over near competitors.

Review by Simon Ingram
First published in Trail magazine August 2013