Roughly how much warmer would I be in a sleeping bag when I used it with a silk liner?

Rab reckon you can get an extra 5 degrees using a fleece liner, but say that silk is more efficent.

It's hard to put an exact figure on how much warmer a silk liner makes a bag without taking the Tasker/Boardman approach of sleeping in a commercial deep freeze. In general I'd say it adds 1 season rating to your bag.

Warmth is only one aspect of using a silk liner, however. The liner also means you keep your down bag cleaner and better smelling - saving money and effort. Silk also adds flexibility to a bag as you can use it on its own in warm weather or adjust how much you zip up your bag. Given the minimal weight involved it's definitely worth the investment. I've used one in everything from British summer to Rocky Mountain winter and wouldn't be without it.

I don't think a silk liner makes any difference at all to the season rating.

I have a Rab technical one for the following reasons:
It feels nice against the skin
It keeps your sleeping bag clean
It is very easy to wash and dry
It packs down small and weighs almost nothing.

sorry to argue guys but i find liners a real pain and end up wrapped up like a christmas turkey by morning i used one with my snugpak bag but didnt find much if any difference

I've a silk liner and would say it while makes a slight difference in warmth, the big advantage is like Dave says it keeps the sleeping bag cleaner.
Only prob I find is that they seem to be just not quite long enough.

I use a Sea to Summit silk liner and pretty much agree with Jonny on this one.

OK I'm probably wrong about the warmth, I never have a problem with the cold anyway. I stand by the other comments though.

I find a silk liner certainly gives added warmth and as has been said keeps your down bag clean I also agree that you can control your heat better with one if you need to be cooler then undo the bottom of your bag and if it gets cold pull it right up over your head and do up the baffle.

As to them being too short, have a look at Jag-Bags web site and choose one to fit, or contact them and they will make one for you.

Very little increase in warmth in my experience but useful for all the other reasons given above

I'd call it a half-season increase in warmth. Considering the tiny weight and bulk it's great value. And apart from the absolute temperature advantage it allows you to discard some clothing that you would otherwise have worn in the bag, which you may well find more comfortable. I'd rather be in a liner than in tracky bottoms or whatever.

I have just been to Torridon and slept in my silk lining for a week using my sleeping bag like a blanket for extra warmth. Soooo much more comfortable than sleeping in a synthetic bag.

does anybody know anything about MERAKLON liners?

lots of people recommend the silk liners for all of the above reasons, but one shop suggested meraklon because of its wicking properties?
whats best with a down bag?
need to get one for my new bag (dreamcatcher 1000)! -v.warm!!!!

Well I got meself a cotton one and a silk one for my new down bag! :)

Anyone got any advice as to which will be more comfortable in warm weather!

No idea about Meraklon, though.

Meraklon's like a typical baselayer-type fabric. Warmer than silk / cotton, but not as warm as a fleece liner, which is what I'd look for to up warmth. Or look for a pile liner, which will be bulky and heavy but significantly warmer again.

I use a Coccoon silk/cotton mix and that works really well in most conditions and isn't quite a filmy and prone to twisting around you as a pure silk liner, while still feeling nice and silky if that makes sense.

I was in me Vango Venom 225 [ a lightweight 2season down] bag the other night and it got a bit parky. Being an idle sod I grabbed my microfleece liner and wriggled into it IN my sleeping bag. Got warmer straight away and went back to sleep OK.
Now I know that isnt the 'proper' way to do it but it did save an awful lot of faffing around in the wee small hours, tho I dont think it would work with silk or cotton.
Anyone else done it t'other way round?

James, silk liners can stick horribly in clammy weather. I'd suggest using cotton on hot nights when you'll probably be outside the bag anyway.

The're no significant difference in pack size, ie, they both fill the wee stuff sac I use. The silk is probably a few grams lighter (depends on the styles) and maybe a tad warmer in winter.

If I didn't have either, I'd look hard at Jon's suggestion

Thanks for advice, Prismatix. Jon's halfway house sounds like an excellent compromise...ah well mebbe when these liners have had it, I'll allow myself one of those! :)