UKH

In a recent archaeological dig in my loft I discovered the above in a layer which is believed to date to the late 90s. It's been stored "unstuffed" so still fluffs up well and looks as good as new...however, I'd like to give it a wash but can't remember what the filling is? Can anyone shed any light on this (and the season suitability...it looks a good 2/3 to me?

Doh! A simple look inside the bag reminds me that it is down...clues as to its seasonality still appreciated!

How much does it weigh?

No knowledge of this bag I'm afraid but being named Polar suggests it's a winter bag and the 500 most likely denotes fill power (which, if true, is quite low so I imagine it's pretty bulky packed}. That said without knowing the fill weight a guess to it's warmth is impossible, personally I'd try it out to test it. 

Was fill power even a thing in the 90s? The 500 is more likely just a model number.

Or the weight of down

http://www.smhc.co.uk/objects_item.asp?item_id=33436

The full ad for the sleeping bag range

http://photos.imageevent.com/imagedude/bbladeupload/bags.jpg

That 1960/70s 'polar' was just one model, and was the top of Black's range of sleeping bag. A mid range Icelandic was my first decent sleeping bag, after a very cheap model from Woollies that I had for Scout camps.

Just over 1.3kg...which seems a lot? Will have to check how much "modern" bags weigh!

Those adverts brought back some memories. My Polar sleeping bag is long gone but the Optimus paraffin stove from back in the 70s still works.

This.  Definitely not fill power.  The down weight as a model number is a common system.