What’s the lightest, most breathable shell there is?

Nothing more breathable than Paramo and similar systems (the other main one being Furtech). Seems fairly popular over in the UK, though it has detractors and critics.

My pump liner weighs 8 oz, and i combine that with a Houdini (around 4 oz), but i'm already bringing the Houdini and the "pump liner" also acts as a mid/thermal layer, so no need to bring one of those.

Not so good for temps above 45/50* F while being active though.

Chris Townshend wrote a good article about it here. Think there are a couple more besides, as well.

Montbell Versalite (6.7oz, pitzips) Worst breathability, lightest weight,lowest cost
OMM Aether Smock and Jacket (7.2oz, eVent DVL)2nd beast breathability, 2nd lightest, medium cost.
Westcomb Shift LT (lightest neoshell at 11.3oz MEDIUM) highest breathability, heaviest, highest cost.

One problem with pit zips is that when your are wearing your backpack the pit zips will not dissipate humidity between your shoulder strap and hip belt. The backpack and its straps keeps the jacket tight against your cloths. as a result air circulation will not extend very fare.

Additionally the none-porous polyurethane has minimal breathability at low humidity levels and only breaths well at high humidity levels. As a result the air inside the jacket has to get saturated with moisture before it breaths. In comparison the air permeable event and neoshell will essentially have maximum breathability at all humidity levels.

So what you need to ask yourself is what is most important, cost, breathability, or weight. The most breathable fabrics cost and weigh more. None-porous polyurethane fabric cost less and weigh less but don't breath as well as Event or Neoshell. Also note the OMM Aether Smock uses the heavier 3 layer Event fabric not the lighter 2.5 layer DVL Event fabric.

Next to combining a (Nikwax analogy) "pump liner" with a windjacket, this is probably your most breathable and lightest option: It's a poncho made out of WPB material. The material itself has decent breathabilitiy and of course with a poncho design you'll get extra breathability especially when there is wind.

http://lukesultralite.com/pertex-backpacking-poncho

However, the issue is that the coating isn't very durable. More like moderately durable.

Thanks Justin and Steven.

I have the Shift LT, it's great on breathability, w/o the pitzips. But definitely heavy at 11oz, relatively speaking.

I hear you on backpack pitzip blocking and dry weather air circulation for poly jackets. What I found is that with newer SUL packs (Zpacks, KS, etc) the straps are thinner and more contoured around the body. Pitzips work pretty well for those, there's just less blockage. There's noticeably more air circulation with pitzips when going uphill with a tiny pack. The bigger packs, like a standard Gregory, Osprey, etc, block the pits.

Regarding cost vs. weight/breathability. Cost is not an issue, I'm approaching it from a pseudo-science "just gotta solve this nut" way. If there is a eVent DVL (or similar) jacket below 7oz, that's the sweet spot. Stuff I found so far, in addition to the first post:

7.2 OMM Aether Smock L (eVent 3L)
8.5 OMM Aether Jacket L (eVent 3L)
9.2 Westcomb Focus LT (eVent DVL called them for exact weight)

Any others you can think of? One thing about all of the above is that the hoods on each are really thought out and don't slide on/off the face in heavy wind. If the hood does not have adjustments it becomes a flap in the wind and goes all over the place. Zpacks could def improve their jacket in that area. I still quite like, just wish the breathability was better.

So you're only interested in eVent and Neoshell?

If that is the case, sorry for the side tracking.

Interested mostly in jackets/anoraks that breathe well or have pitzips. Mostly eVent and Neo and other similar air porous stuff. Similar material by Mountain Hardwear, Marmot and Montbell.

I use both Neoshell and event and don't notice a massive difference, but I do notice it when using Paramo, but I only use Paramo in winter.

Not much help really.

The MH Super Light Plasmic is a nice eVent 2.5L jacket at 7.7oz. You can great deals on them occasionally. I got mine for about $80 off Amazon. The weight is similar to the other offerings and the price is often cheaper. I know price isn't a factor for you, just throwing it out there.

Ryan

There's a great Neoshell Anorak from EMS, the Helix. 11.4oz with a pit zip on one side and a FULL zip on the other. It's also much cheaper than the competition. When I bought mine, it was $124. Right now it's not on sale, so it's $250, which is still good.

I have the EMS Air Flow. Event DVL (2.5l). Pitzips. Mine weighs 11.5 oz in size XL. Bought it on sale for $150.

Marmot BWP laminates are NOT similar to eVent either in breathability or durability.

eVent laminate is far more breathable than any Marmot laminate.

Skin! I have given up on "breathable" shells. As well as clean coal, fat free food that tastes good, Santa, unicorns and other myths. I switched to ponchos, rain skirts/kilts, and chaps years ago. Yes, they can handle windy conditions, yes they are durable, yes you can move in them unless you are in a bushing whacking ultra-marathon adventure race, and yes, they really do ventilate. One of my ponchos doubles as a shelter and the other doubles as a groundsheet. Try that with a jacket.

Sure, I look like a third grader who got lost during recess, but I am warm, dry and comfortable. Let go of the dream and the illusion, the spell of marketing and empty promises. Let go of the over heating, the sweating, the clamminess, the dampness, the wetness. Let go of the crazy up front cost and the endless on-going wash in maintenance for garments that always fail and disappoint. Throw on a poncho, amigo, find you inner child, jump in some puddles and finally be comfortable in the rain and in your own skin.

////end of rant and thread drift////

Edward, please make some specific brand/model recommendations for ponchos.

I liked your rant and mostly agree Edward, but of course i would modify it some. (segway) Speaking of modification, for the most part i like ponchos. But to me, it seems like a no brainer, why not use some WPB material for part of a poncho (the part that goes over front core especially). It's one of those ideas that is so simple, that few seem to think about it. One could always use more breathability, and if one is willing to do some mods, you don't have to pay much for such alterations and they are pretty easy. You're basically just cutting a rectangular of fabric, sewing it on to the poncho, and then cutting away the original fabric for that area. Piece of cake.

I bought two Sierra Designs brand–"Storm Poncho's" on sale for 15 each, weight at 7.9 oz (a bit on the heavier side as compared to some all silnylon ponchos). I just finished moding one of them today. It does look a bit funky being a combo of blue (original fabric), green (front core highly water resistant, quite breathable fabric), and dark brown (replaced much of the back with lighter silnylon). I could care less how it looks though.

This will be my go to rain gear for warmer weather. (the other will be modded with my own 3 layer WPB design using 1443R tyvek as the "membrane" and polyester organza fabric as the lining and shell).

For colder to cooler weather, nothing beats getting a Nikwax Analogy Pump liner, or garment with the same properties, and combining it with your favorite UL windjacket of choice. Though, it will necessitate occasionally deep cleaning and re applying DWR (but less often than with a non epic shell), so it's not ideal by your above standards. One could use one of those military style Polypropylene winter weight, fuzzy on the inside "baselayers", turn it inside out and use that as the mid/pump liner layer (will need to attach a hood though) and not ever need to apply DWR to it, just occasional good cleaning with something that breaks up/dissolves grease/oils.

Anyways, so far these general concepts seem to be the ultimate in breathable, comfortable rain gear, at reasonable weights.

I've read a couple very positive reviews of marmot nano pro fabric. I take this sort of thing with a grain of salt, but you might want to check out this review: http://www.outdoorsmagic.com/gear-blog/blown-away-by-marmots-new-fabric/12549.html

and then consider that the new marmot essence jacket, at 6 oz, is made with nano pro. It also has built in pit vents, which can't hurt. I'm keeping my eye out for one one sale, which should make the $200 retail jacket pretty affordable.

+1 for the Poncho, I agree with everything Edward outlines above. I'm using the Zpacks cuben groundsheet Poncho and I'll never go back to a jacket.

Maybe not the lightest but I own a Rab Demand 3 ply event pull over that's great. Actually REI makes a 3 ply event jacket too. Anyway Rab standards are excellent.

2.5 event is lighter; not sure if it's comparable in weatherproofness. Maybe 2.5 breathes better?

I've found 3 ply event to be really durable and very weatherproof.

What's the size and weight of the Demand?

Mine's a medium and weighs 12 ounces, I think. Rab sizes a bit small. I'm 5'9" and 140. The medium fits perfect. But if you want to wear a puffy jacket underneath, size up for sure. I can 'just' fit a lightweight down jacket under mine without constricting the down; but a heftier down jacket underneath doesn't work.

Umm, I'm not sure that the Demand is still in production.

I've been through some really nasty weather in the rab, including hiking for several hours in cold rain and then up through sleet for several hours crossing a pass. Hypothermia might have occurred without this 3 ply jacket. Since than, I'm happy with a bit heavier 3 ply shell that protects well.

I do like an anorak. Once I have it on.

I think a DriDuck jacket best meets the needs you identified (lightweight, breathable).

If you also need durable I'd vouch for Gore Active Shell

The Emperor's New Clothes
or a cheap cotton T-shirt?

Cheers

Roger Caffin wrote re: lightest and most breathable shell there is, "The Emperor's New Clothes or a cheap cotton T-shirt?"

It would seem that someone convinced Emperor Caffin that he was wearing the latest and greatest in super breathable tops, whilst skiing nonetheless… ;)

I just hope the poor bloke didn't get his head chopped off, once the Emperor realized he really had no top on! (it was rumored though, that the Emperor was quite fond of the colorful bottoms picked out for him).

Delmar – I love the Zpacks Poncho/Grounsheet. I think it is the best design I have worn. The hood and bill are excellent, it has a deep front zipper for ventilation, side zippers, and a built in adjustable shock cord/mitten hook "belt" that allows for easy control in high winds. I pair it with cuben rain chaps. Zpacks has them in several sizes. I am a big guy, so the Twin fits me best. I scored a used Gatewood Cape but have yet to use it. Next week looks like it's maiden voyage. Tests in rainy Seattle look good as both a poncho and a bomber shelter. I have used the Golite poncho/tarp but find it is too minimal for me in shelter mode. But it is light and cheap.

Edward,

I'm in the market for a poncho and you may be the man who can answer my question. What is the appeal of the Zpacks Twin Poncho over the Golite which is a fraction of the cost and less than an oz heavier? I do see that it's cut in a way that will work better in my Hexamid Twin but anything else I'm missing?

Thanks