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Reviews > Sleep Gear > Summer Bags and Liners > Grand Trunk Silk Sleep Sack > Test Report by Kara Stanley

October 28, 2015



NAME: Kara Stanley
EMAIL: karguo at yahoo dot com
AGE: 32
LOCATION: Phoenix, Arizona
HEIGHT: 5' 10" (1.80 m)
WEIGHT: 165 lb (74.80 kg)

I have been hiking most of my life and backpacking since 2006. I have hiked mostly on the east coast, doing weekend trips in the Appalachian Mountains. Since moving to Arizona, my hikes have ranged from short desert hikes to overnight backpacking trips in the mountains. Recently I have taken up canyoneering and off-trail hiking/backpacking to spice things up. I currently use a solo non-free standing tent, canister stove, purification tabs, and lightweight trail runners, conditions permitting, to cut down on weight. My hikes are solo and range from an overnight trip to 4-5 nights on the trail.



Manufacturer: Grand Trunk
Year of Manufacture:
Manufacturer's Website:
MSRP: US$ 69.99
Listed Weight: 5 oz (142 g)
Measured Weight (Sleep Sack and Stuff Sack): 4.2 oz (119 g)
Measured Weight Stuff Stack: 0.4 (11 g)
Listed measurements: 84" x 36" (213 cm x 91 cm)
Measured: 84" X 34.5" (213 cm x 88 cm)
The Sack is sewn 51" (130 cm) up the side from the bottom of the sack.
The Pillow Pocket is 14" (35 cm) deep from the top of the sack.
Sizes: The silk sleep sack is available in single (tested) and double sizes.

The packed sleep sack


This silk sleep sack is small and lightweight! This sack is about 1/3 the size of a 32 oz (~1 L) Nalgene bottle. When I pulled out the sleep sack, it was neatly folded to a long rectangle then rolled into a tube to fit into the stuff sack. After I unrolled and unfolded the sleep sack, I was able to stuff it back into the stuff sack without any trouble.

After removing the sleep sack, I noticed two things. First that the sleep sack felt very soft and smooth. Second, I noticed that the sleep sack was see-through and seemed very thin. It will be interesting to see how the sleep sack holds up since I am a restless sleeper and move around a lot even in my mummy-style sleeping bag.

The sleep sack has two sets of ties along the sides that are not sewn shut. On the left side of the sleep sack, there is a small stuff sack sewn to the sleep sack. This stuff sack seems to be well attached and looks like it would be difficult to remove without damaging the sleep sack.
The Sleep Sack draped over a long mummy-style sleeping bag

Attached Stuff Sack and side ties

Sleep Sack with Pillow


The care directions for the sleep sack say to hand wash the sleep sack. No drying directions are listed. The sleep sack is said to increase the warmth of a sleeping bag by 10 F/ ~5 C degrees. The sleep sack is made from "100% premium silk."


While I have not had this sleep sack out on the trail, I did try it out in my living room. I found that I easily fit into the sleep sack and it came up about mid-chest on me before the sides were open. I was able to pull the top of the sleep sack over my head with ease. I could easily fit my queen-sized memory foam pillow in the pillow pocket, however the pillow was only partially covered by the sleep sack. Since that pillow could fit in the pillow pocket, I know that my small foam backpacking pillow or clothes filled stuff sack will fit with room to spare!

I did not try this out inside my mummy-style sleeping bag because I currently use a rectangular sleep sack without any issues.


Overall, I am excited to test out this lightweight sleep sack as a sleeping bag liner and on its own during the heat of a Phoenix summer (temps can exceed 90 F/32 C at night).

Current Pros:
* Lightweight
* My skin tends towards to sensitive, dry side, so having a silk sleep sack is plus as it does not irritate my skin.
* Easily stuffs back into its stuff sack

Potential Cons:
* Seems fragile and prone to snags (it caught on finger nail)
* Slits on both sides instead of just one
* Stuff sack is sewn onto sleep sack - seems like this could get caught on something and tear from the sleep sack damaging it.



Location: Grand Canyon, Arizona, USA
When: August 2015
Length: 2 days/1 night
Mileage: 18 miles 29 km
Elevation: highest 7,000 ft/2,100 m to lowest 2,500 ft/800 m
Weather: Hot and sunny (High: ~95 F/35 C, Low: 80 F/27 C)
Trail Conditions: well-maintained trail, dry and dusty with some coble stone areas.

Lila Lake, Snoqualmie Region, Washington, USA
When: August 2015
Length: 2 days/1 night
Mileage: 11.0 miles/17.7 km
Elevation Gain: 2,800 ft/853 m
Highest Point: 5,400 ft/1,646 m
Weather: Warm and mostly sunny with an overnight shower (High: ~80 F/27C, Low: 50 F/10 C)
Trail Conditions: Well-maintained, mostly dry and dusty, with patches of talus and some marshy trail.

Baldy Loop, Eastern Arizona, USA
When: August 2015
Length: 2 days/1 night
Mileage: 17 miles/27.4 km
Trailhead Elevation: 9,394 ft/2,863 m
Elevation Gain: 2,250 ft/686 m
Accumulated Gain: 2,880 ft/878 m
Weather: Rain for the first few hours at the start, then warm and mostly sunny for the rest of the hike (High: ~80 F/27C, Low: 50 F/10 C).
Trail conditions: A mix of rain water covered trail (about 1 in/2.5 cm of water at times), and dry and rocky. Overall, the trail was well-maintained.


I have taken this sleep sack on three trips so far. I have used it by itself as well as with a 30 degree (-1 C), 875-fill down mummy style sleeping bag. For the trip to the bottom of the Grand Canyon, I took the sleep sack, a lightweight air mattress, and slept on a tarp under a shelter. I found that the pillow pocket in the sleep sack fit over the top of my air mattress to keep the sack on top of the mattress. I liked that, by doing this, my head was always on soft silk and not the plastic air mattress. I only used the sleep sack to cover the lower half of my body since it was around 90 F (32 C) for most of the night. I could feel a warmth difference between covered and uncovered parts of my body. This sleep sack kept me warm all night, not once did I wish I had brought somthing else to cover my body with. As a restless sleeper, I liked the added room that the rectangular shape provided, which allowed me to sleep with my knees pulled up by my chest.

The next two hikes I used the same sleep system of a 30 F/-1 C degree down mummy bag, air mattress, and a 3-season tent with the rain fly on, which I shared with another person. While the sleep sack is rectangular and the bag mummy style, this was not a problem and I never thought about it on either trip. I loved the feel of the silk against my skin at night as it was comfortably cool and soft. I did find that when I used it with a sleeping bag, if I tossed too much I would end up with one of the slit sides on top and open so that the upper part of my body was not covered.

I used the sleep sack for all three trips without washing it between trips, due in part to the fact that the trips were on back-to-back weekends and the sleep sack needs to be hand washed and I didn't have time between trips. I didn't notice a smell to the bag after these trips. I recently washed to sack using hand soap and my bathroom sink and hung it over the shower curtain rod to dry. It dried completed overnight, but since Phoenix has low humidity, this is the expected result. Since it is hand wash only, I cannot just throw it into the washer with all my dirty hiking clothes like I can with a non-silk liner. However, at this time, this is a pretty small trade off for a small, light, super soft liner. We'll see if I think this way in two months after many more nights in the woods.


Overall I like the sleep sack so far and its holding up pretty well.

* Light weight
* Small packed size
* Feels great on the skin
* Provides noticeable warmth when used alone

* Slit on both slides
* Hand-wash only



Colorado Trail, Creede to Silverton, Colorado, USA
The seam wear

When: September 2015
Length: 12 days/11 nights
Mileage: 80 miles/127 km
Hiking Elevation: mostly between 11,000-13,000 ft/3353 m-3962 m
Weather: Temps from about 30 F/ -1 C to about 75 F/24 C, with all weather types represented on this trip - rain, sleet, wind, clouds, and sun.
Trail Conditions: Overall, the trail was well maintained though steep in some spots.
Estimated pack weight at the start: 45 lbs/20 kg
Use: Nightly, with one full day spent in the sleep sack due to poor weather conditions.


I feel that I should note again that I am a VERY restless sleeper, especially at high altitude (greater that 10,000 ft/ 3,000 m).

For the first part of the trip I used it as a sleeping bag liner inside of my 15 F (-9.5 C) degree sleeping bag as that was the coldest part of the trip. As we got lower in elevation and the temperatures warmed up a bit, I used the sleep sack directly on my air mattress with my sleeping bag opened and used like a quilt. When using the sleep sack directly on the air mattress, I hooked the pillow pocket over the top of the mattress to keep the sleep sack in place. I loved how the pillow pocket kept the sleep sack in place despite my restless tossing during the night. My sleeping bag is mummy style and this sleep sack is rectangular, I never found this to be an issue.

Over time, I found that the attached sleep sack to be a pain - literally. During my nighttime tossing and turning, I would end up sleeping on the stuff sack and its plastic drawer string toggle. I wish that the stuff stack was detachable.
The 7.5 in/19 cm tear

That being said, the 11 night trip put a lot of wear on this sleep sack and it shows it. I enjoyed the softness and warmth of this sleep sack, not once did it irritate my skin. But on the fourth night this stack started to tear, right where the seam started. The tear grew during the trip and at the end it was 7.5 in (19 cm). After the tear started, I used the ties to tie that side up in hopes of preventing the tear from growing. The tie lasted for a few nights, but by the end of the trip one the side ties had ripped off. Additionally, there pulls in the fabric (see picture) on both the top and to bottom.
Fabric wear/pulls

I think that if the fabric has some give to it or was make of a knitting silk fabric, the tear may not have occurred and the seams and fabric would not have pulled.

At the end of the 11 day trip, the sleep sack didn't have a noticeable smell. I hand washed the sleep sack and hung it over my shower curtain rod to dry.


* No smell, even after 11 nights in a row, including one full day.
* Soft and did not irritate my skin
* Light weight and compact
* Pillow pocket fits over an air mattress to keep it in place

* Very delicate - shows much wear after the long term test
* Fabric has no give or stretch
* Having both sides slit about 1/3 of the way down - I would have liked only one side slit.
* Not sure how much wear is left in the bag after the testing period which (totaled 14 nights)
* Attached bag could end up under a restless sleeper at night, which was painful

Now that the testing period is over, I will sew up the tear and one of the sides. Even though the sleep sack has some wear on it, I will continue to use because it is soft, compact, and lightweight while still adding warmth.

Thank you and Grand Trunk for the change to sleep in this sack! This report concludes by test series.

This report was created with the Report Writer Version 1. Copyright 2015. All rights reserved.

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