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Reviews > Stuff Sacks > Compression Sacks > SealLine Compression and Cinch Sacks > Test Report by Kathleen Waters


INITIAL REPORT - March 26, 2019
LONG TERM REPORT - July 10, 2019


NAME: Kathleen Waters
EMAIL: kathy at backpackgeartest dot com
AGE: 68
LOCATION: Canon City, Colorado, USA
HEIGHT: 5' 4" (1.60 m)
WEIGHT: 118 lb (53.50 kg)

Living in Colorado and being self-employed, I have ample opportunities to backpack. There are over 700,000 acres/280,000 hectares of public land bordering my 71-acre/29-hectare "backyard" in addition to all the other gorgeous locations which abound in Colorado. Over the past 15 years, my husband John and I have also had the good fortune to hike/snowshoe glaciers, rain forests, mountains and deserts in exotic locations, including New Zealand, Iceland, Costa Rica, Slovenia and Death Valley. My hiking style is comfortable, aiming for lightweight. I use a tent (rainfly if needed). Current pack averages 25 lb (11 kg) excluding food and water.



Manufacturer: SealLine, Division of Cascade Designs, Inc.,
Year of Manufacture: 2019
Manufacturer's Website:

MSRP: US $25.95 for 20 L Cinch; US $28.95 for 10 L Dry

Other details:

* Made in China
* PVC Free
* Roll Top Closure (Dry Sack) / Locking Cinch (Cinch Sack)
* Welded Seams
* PurgeAir Valve (Dry Sack)
* Continuous Compression
* 20D Nylon
* Waterproof (Dry Sack) / Splash-proof (Cinch Sack)

Technical Specifications20 L Cinch Sack10 L Dry Sack
Listed Weight4.5 oz (128 g)4.4 oz (125 g)
Measured Weight4 oz (113 g) 4 oz (113 g)
Listed Width5.5 in (14 cm)4.3 in (11 cm)
Listed Length10.4 in (26.5 cm)8.2 in (21 cm
Listed Height18.8 in (48 cm)14.1 in (36 cm)
Listed Volume1220 cu in (20 L)610 cu in (10 L)


IMAGE 2 Ok, my first impression of the SealLine Block Compression Sacks focused on the retail packaging. The long slim hard plastic hang- able packs are frosted with a little clear window that let me set immediately that despite the SealLine website colors listed as "navy" and "orange", my sacks are light blue and green! Minor, irrelevant detail, but that was my immediate thought. Wow, I like these colors!

Next, after I removed the sacks from their respective packages, I was able to inspect the closures - cinch and roll-top, the quality of the material and the compression straps.
The material is light but very sturdy. I gave some gentle tugs and feel pretty confident about the secureness of the seams and the sack's strength. All the stitching appears even with no snags or loose threads. In places where the seams are sealed, the fabric is smooth with no puckering.

The top closures on the sacks are just what I would expect from their respective description. The cinch top closes with a draw cord and barrel lock and the roll-top seals the sack by rolling downward and being secured in place with a plastic clip.

The compression system is very interesting and different from any other strapping system I've had. There are four straps sewn crosswise that are attached to a bottom cap-like piece which is attached to the sack. These same straps are also attached to the top free-floating cap which covers and seals the top opening to the sack when the compression straps are tightened.

When the compression straps are properly aligned and tightened, the sack looks like a gift box with ribbons in the usual manner.
Lastly, on the dry sack, there is a round black foam insert labeled "Purge AIR".

I have to confess, I was totally boggled by the manufacturer's measurements of width, length and height. It took me a while to realize the listed width and length measurements are taken from the width and length of the "end caps" which are in fact, rectangular. I pulled out my trusty tape measuring device and concur with the manufacturer.

Where I'm still scratching my head is over the height numbers. First, I would suspect the height to be dependent on how stuffed the sack is. But simply measuring the sack empty from top to bottom, I get a height of 20.5 in (52 cm) for the cinch sack and 19 in (48 cm) for the dry sack. Interesting.


SealLine includes printed instructions on how to use and how to care for both the compression cinch sack and the dry sack. There are also videos on the website under the respective products which while they aren't strictly instructional - more like, advertisements - do show how the bags work.

For the compression cinch sack, only three steps - both in text and pictures - are given: 1.) how to open the cinch sack by pulling the cord lock away from the sack; 2.) how to close the sack by pulling on the cord and sliding the lock into place and 3.) how to compress the sack via the compression straps. Opening and closing the sack are intuitive, pretty much the same as using any drawcord and cord lock closure. Compressing the sack is accomplished by pulling evenly on the four compression straps after the compression cap is place over the cinched closure.

There are four instructions given for using the compression dry sack, including handy graphics to illustrate the steps. 1.) hold the sealing strips together; 2.) while holding the strips together, push down on the bag to squish out the air and then tightly fold down the top over a minimum of three times; 3.) connect the buckle and 4.) put the compression cap over the roll-top closure and tighten the compression straps evenly.

As for care instructions, both the cinch and the dry sack should be cleaned and aired out after each use. If needed, hand wash using a soapy sponge and thorough rinse. Sacks should be stored when completely dry, both inside and outside.

When packing the sacks, sharp items should be wrapped or padded with softer items to prevent tearing the fabric. And lastly, care should be taken to keep the fabric from contact with insect repellents and other solvents..


As soon as I released the sacks from the very neat retail packaging, I just had to try them out! Since I've used stuff sacks before, I knew generally how the cinch and dry bags would work.

Sitting in my home office, I grabbed an afghan and proceeded to roll and stuff it into each of the bags in turn.

First I tried the dry sack. The smooth surface of the bag made it easy to slide the blanket in and I quickly was able to roll down the top and squeeze out all the air via the "air purge" valve on the side of the sack.

Once the sack was nicely compressed and the connector clipped in, I put the cap over the top closure to seal it up. I confess to have taken more time than I'd like getting that top to stay in place while I tightened the compression straps. It's a slippery little bugger!

However, I was able to employ some patience and evenly pull the compression straps into place, keeping the cap secure and then - Voila! - I had a nice neat compressed sack!

I used the same afghan to try out the cinch sack. Since the cinch sack is twice the size of the dry sack, I had a lot of extra space, so a lot of extra material to fold over under the compression cap. I found myself wishing for an extra set of hands, but was able to make a nice, but less-neat-than-the-dry sack!

I'm hoping that practice (and more content) will make it easier in "real" use.
Empty Dry Sack
Empty Cinch Sack


The SealLine Blocker Compression Cinch Sack and Dry Sack appear to be well-made and easy to use. I am excited about the chance to protect my gear from dampness this summer, especially when on kayaking and fishing camps! I also will be using them for food storage on the Colorado Trail as "bear bags', so that should be interesting as well.
Ready to Go!



Over the last two months, my one and only outdoor outing where I had the packing space for camp shoes took place over a weeklong Fourth of July holiday base camp for fishing at Lake Pueblo State Park in Pueblo (El Paso County), Colorado.

Temperatures ranged from 54 F (12 C) at night to a high of 97 F (36 C) during the daytime. It was mostly sunny in the mornings with super strong winds and clouds in the afternoons and early evenings. We had a couple of rain showers in the afternoon and one very spectacular lightning storm one night!

Since we were in an established campground, the terrain was groomed but the fields were covered in prickly pear cactus and sharp yucca plants. The shore line of Lake Pueblo was very rocky at our campsite.


Alas, my Colorado Trail plans have been pushed back a bit to early September, so I was not able to report on the use of the SealLine Compression dry and cinch bags as bear bags.

However, I did get to use them on several day hikes and on our fishing camp in early July.
They worked wonderfully for packing my gear into small neat "packages" which helped save valuable storage space for things like food!

My initial struggles with the 20 L compression dry bag's cover have been resolved and I've gotten pretty adept at cinching down the bags to the smallest size possible. Having the air purge valve is a big help there. Amazing how much space "air" takes up!

Mostly, I've used the bags for clothing articles and my sleeping bag. Yet I still can stuff even my Big Agnes Fria 15 sleeping bag in when needed into the compression bag!

I like using the smaller 10 L cinch bag mostly for undies, socks and tank tops which usually get "lost" among my other belongs. I can get 5 pairs of panties, base layer top and bottom and 5 pairs of socks in there with plenty of room to spare.

I also love that the bags sport bright and different colors so that I can find them easily and I can know (if I actually remember) which bag holds what!

I can attest to the water resistant of the bags as I left one out overnight accidentally and though it wasn't a hard rain, we did have some drizzle. Everything inside the bag was perfectly dry and the bag dried out very quickly when hung over a branch to dry.

I also took the smaller 10 L cinch bag out on our kayak for a bit to see how it would handle my sloppy paddling - I tend to get soaked. The bag kept my sandwich and potato chips edible! Yay!

I have yet had to do any real cleaning of the bags. They pretty much have held on to their good looks with no staining, tearing or fraying of material. The closures all are tight and functional.


For an organization freak, storage bags/boxes/whatever are a necessity and good ones inspire creative ways to take along MORE! These BlockerLite compression and cinch dry bags for SealLine are the answers to that need to organize and protect my belongings no matter where I am going. They are spacious, easy to use, tough and water-resistant. What more could I want?

Thank you to and SealLine for the opportunity to try out these compression sacks!

Kathleen (Kathy) Waters
Co-Owner and Contributing Writer

This report was created with the Report Writer Version 1.5 Copyright 2019. All rights reserved.

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