Wakefield Wanderings

So what exactly is a ‘liner’?  Well, it is short for ‘sleeping bag liner’, but does not have to be used in a sleeping bag.  It is basically a tube of fabric, the size of a sleeping bag, closed on one end for your feet, and open on the other end for your head.  It can be used inside a sleeping bag to provide additional warmth or it can be used alone as a bag all by itself if it is not cold where you are sleeping.

In my case, I bought it to use for additional warmth, and to keep my sleeping bag or down quilt (more about quilts another time), cleaner. This reduces the number of times I have to wash my bulky bag or down quilt or sleeping bag. The silk has the advantage of being much lighter than other materials, and it will not retain moisture like cotton.

Product Information:

There are several sizes and styles available. In this case, the review is for the Long (Rectangular) size.

The 100% Premium Silk Liner is made from ripstop silk, and is sewn into a rectangular sleeping bag shape. According to the manufacturer’s website, it adds up to 10 degrees F (6 C) of warmth to an existing sleeping bag. It is machine washable, and stuffs into its own included stuff sack. I have the long (rectangular) size, but other sizes are available, according to the manufacturer’s website:

The silk liner can be used as a very lightweight bag by itself if temperatures are warm, or as a liner inside any sleeping bag to add warmth on colder nights.

Field Testing:

I have used this silk liner on my last four camping and backpacking trips for a total of eight nights. Temperatures at night got as low as 22 F (-6 C) on a four night trip, and below freezing on the other three trips. I have used the silk liner both inside a mummy winter sleeping bag, and underneath a down quilt.

It is difficult for me to know exactly how much additional warmth the silk liner provides. Based on previous trips when I had to wear a base layer of clothing inside my mummy sleeping bag to stay warm below freezing, I was able to use only the liner, and no base layer of clothes, to stay comfortable. I believe the 10 F (6 C) of additional warmth is reasonable.

When using the liner, I also get the benefit of it keeping my sleeping bag or quilt cleaner. The liner prevents body oils or dirt from getting onto the inside of my bag or quilt. When using the liner with the down quilt, the liner prevents some drafts from reaching me around the edges of the quilt. With either a bag or quilt, I slip my feet into the opening on the liner and pull it up to my shoulders. With a quilt, I just pull the quilt over me. The quilt does seem to stay in place, even though the liner is slightly slick. With a sleeping bag, I put my feet into the liner, then push the liner down into my sleeping bag as I pull the liner up to my shoulders. I can keep my arms out of the liner to zip up my sleeping bag. Usually, if it is cold, I will pull the liner up around my neck as well for added warmth.

I also think that having the silk liner inside my sleeping bag, which gives me the ‘bag within a bag’ system, makes the sleeping bag feel warmer by keeping warmed air around my body within the liner. When I move, my skin does not touch the inside of the bag directly, so it seems that there are fewer ‘cold spots’. With just a sleeping bag, if I move my leg or foot to an area of the sleeping bag that I had not been touching, then that area of the bag feels cold. The liner feels soft and smooth against my skin, and the silk material does not feel cold when I move around inside the liner. The liner has two side seams, and no bottom seam. Both seams are double folded, and I have not noticed feeling either of them when using the liner.

The rectangular liner is larger than a mummy sleeping bag, but the extra fabric fits fine inside the mummy bag. I have not noticed any problems moving my feet or legs around when using the liner inside a sleeping bag. The fabric is slick enough that it slides around inside my sleeping bag and does not restrict my movements.

I have washed the liner about six times. Per the instructions, I washed it in cold water and then hung it to drip dry. I have not noticed any fading or bleeding when washing the liner. I have noticed some slight stretching at the seams near the top of the bag. I think this is due to the fact that as I turn, my arms may be pulling or stressing the top portion of the seam.

I decided to contact Sea to Summit to see what they had to say about this. I received an email reply within 24 hours stating: "…I’m sorry to hear that your liner hasn’t worked out for you as well as you (or we) had hoped. Our product is 100% covered for manufactures defects—which this is clearly a case of. We sell thousands of these liners each year and see very few ever returned to us. With that being said, we would be happy to replace it for you free of charge…" They provided an RA number and shipping address with the reply as well.

So, although the seam is not torn apart or separated completely yet, I went ahead and exchanged it. Perhaps this one seam was defective. It only took 6 days from the time I mailed the defective one back until I received a brand new replacement silk liner from Sea to Summit. I was very pleased with the customer service from Sea to Summit.

Pros:

• Lightweight
• Adds warmth
• Keeps sleeping bag clean
• Great customer service

Cons:

• Somewhat expensive
• Had to return for replacement

Summary:

By using the 100% Premium Silk Liner from Sea to Summit, I am able to keep my sleeping bag or quilt cleaner which results in fewer washings. The silk liner adds warmth on cold nights and it works well under a quilt to prevent drafts. I always pack the liner when my trips may include colder weather. I look forward to receiving the free replacement and continuing to use the liner in the future.

- Shawn