Sea to Summit Stuff Sack vs Ultra Sil Stuff Sack Review

Water resistant storage and organization is essential on and off the trail. Be it to protect your food, clothing, or really any other great, a good stuff sack can absolutely save a trip when the rain dumps down unexpectedly. Today I compare the Standard Stuff Sack to the Ultra Sil Stuff Sacks from Sea to Summit, and review them both.

Ultra Sil vs Stuff sack side by side

Starting out, I’ll be comparing the 9 liter “stuff” sack to a 9 liter “Ultra Sil Stuff” sack to keep the numbers directly comparable. Also note that the products pictured are not those exact sizes, just what I had on hand at the time.

So, what is the difference between the Stuff Sack and Ultra Sil Stuff sacks? Well, primarily, it is material and weight. The tradition ‘Stuff Sacks” are constructed from light yet durable 70 denier nylon. The fabric is water resistant and can take a considerable amount of abuse, be that scuffs and scrapes, tension or just being wadded up over and over. It is equally at home on the trail as well as on the water for paddling, although the closure is not water tight (that would be a “dry sack”, with a roll top enclosure which they also make) and they’re also not seam sealed. That being the case, they’re not water proof, just water resistant. These weigh about 1.8 ounces for the 9 liter size. The heavier Stuff Sacks also have a vigorously reinforced opening, with a tougher material and extra stitching for maximum durability.

Comparison Fabric

The ‘Ultra Sil’ sacks are less than half the weight at the similarly sized 8 liter size at about .7 ounces. This is achieved by using 30 denier Ultra Sil Cordura fabric and using less reinforcement and smaller cinch locks. This fabric is incredibly lightweight, still highly water resistant, but not quite as durable as the thicker nylon used before. The Ultra Sil variant does however use Ripstop, which helps stop tears from spreading if they do form, which is missing on the thicker Stuff Sack.

Sil Stuff Sack Closure

They both have cinch style enclosures with a plastic buckle, but the heavier ‘Stuff’ variant models use a larger adjustment mechanism which is a bit easier to grab and more durable as well. The Stuff Sacks are a bit cheaper too, usually ranging 3 to 5 bucks cheaper than their ‘Ultra Sil’ variants.

Stuff Sack Closure

Which is better?

Which stuff sack is better really comes down to the use case, and it’s actually rather simple.

Generally speaking, for most, the Lightweight “Stuff Sack” model is going to provide all the protection needed, with the added durability of the higher denier nylon fabric. making it more of a do it all stuff sack. The Stuff models also make for great multi-discipline sacks, as they can be easily carried between hiking, backpacking, kayaking and even emergency preparedness. They’re light, convenient, and the added affordability is very nice. They’ll hold up longer to repeat abuse, especially useful if they’re being laid across rocks and pulled in and out of packs often.

However, the Ultra Sil sacks offer the most advanced materials and absolutely minimal weight. They may not be quite as durable, but for most cases they’re more than adequate. When backpacking, I especially like to lean to the Ultra Sil variants. They pack down tiny, weight very little, and will have no trouble shedding monsoons of rain time after time. Paired with the added protection of a backpack, these sacks will last a long time without adding any weight burden, given a little TLC is applied. These are light enough that I can keep an extra in a backpack or even a front pocket just in case I need to shed layers or re-organize on the trail. These really are the option for those who are counting ounces, or even grams, in pursuit of the absolute lightest pack weight possible.

Side by side


Both the Ultra Sil and tradition Stuff sacks are great options for the trail. They’re both incredibly lightweight, extremely useful, and should be a part of every backpacker and hikers kit. Very few pieces of equipment are useful when they’re soaking wet Afterall. My favorite sacks, personally, are the Lightweight variant as I can use them in an infinite number of situations, and I find myself being way rougher with them than I probably should. I like the added durability, the cost savings, and I don’t generally find myself obsessing too much above weight. However, when I’m really doing the distance, the Ultra Sil make a lot of sense. Honestly though, I have no complaints about either model and I likewise have no reservations suggesting them to anyone.

Ultra Sil vs Stuff sack

Highly Recommended

Want to learn more about this product and their other offerings? You can check out their products Here. This is an affiliate link and helps me out. Below is a link to their waterproof Dry Bags, which I also recommend especially for water sports.

For information on our rating system and our testing procedures, check out our About us/ Contact us page.

I want to extend a huge thanks to Sea To Summit for providing this product for review. We couldn’t do it without their help.

Our full disclosure can be found on our about us page. Thanks as always for reading! Don’t forget to follow our blog for future updates and reviews (link on the right also).

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