Ultralight Outdoor Fabrics 101, a simple guide to the fabrics I use.

The outdoor industry can be a little confusing for customer in terms of fabrics and material used in their products, brands often claim to use the best fabric ever or the most durable or the most shiny and beautiful and miraculous and….

I think the perfect fabric doesn’t exist (yet) and I chose to use products of a company that ticks all the boxes.

Since the beginning I use Challenge Outdoor fabrics, made specifically for the outdoor industry.

They have a great range of products, every fabric has a specific range of usage and different price point and, most important, they produce sustainable materials in a sustainable way.

Some fabrics are made with 100% recycled polyester, some are partially recycled, some are good for all round products, some are very technical and pricey.

I also use some fabrics produced by other companies.

Below you can find all the fabrics I use with a short description, for more technical data please check out links.

Challenge Outdoor Fabrics

Ecopak EPX200

Ecopak EPX200 is an all rounder fabric, made with an outer 200d and an internal 70d ripstop polyester fabric, one of my favourite for every kind of product.

Pretty durable and light at the same time, sheds water very well and dries very fast if gets wet.

The fabric itself is waterproof but can’t be seam taped, products made with Ecopak EPX can’t offer a 100% shield from the elements.

What I like about this fabric is the stiffness and the colour range available, the fabric is a little shiny and colours are vivid and beautiful, from the classic Black Knight to a bright and outstanding Pink Flamingo, Ecopak EPX200 offers colours for every taste.

It has a cross ply structure between the face and backing to add structure, may be more or less visible depending on the colour.

A perfect fabric for backpacks and accessories where extreme durability it’s not needed (eg. alpinism, scrambling).

This is my go to fabric for my personal Loop 20L backpack and Mio fanny pack, I also made some bike panniers, a handlebar bag and a hip pack with it and I’m not disappointed. Never had a problem with rain too.

If you look for a beautiful and affordable fabric, Ecopak EPX200 is the right one.

Made with 100% recycled polyester 😉

Ecopak EPX400

Stronger (and heavier) version of Ecopak with a 400d face fabric, it comes in less colours and can be used in specific areas like bottom panel of a pack or others parts exposed to high abrasion.

For a daily usage it can be overkill, specially if you take care of your gear.

If you tend to throw your pack on granite rocks or hike in tight canyons this may be a solution to reinforce some parts of your pack (or you can opt for Ultra).

Made with 100% recycled polyester.

Ecopak EPLX200

Things start to be a little confusing eh?

EPLX is a lighter and cheaper version of Ecopak with no backing fabric, instead you will find a shiny film that can be taped (hurray!).

I like it for “waterproof” UL packs or accessories where abrasion resistance is not an issue.

Limited colour range.

Made with 100% recycled polyester.


As the name suggest this is an ultra fabric!

Pricey, yes it is, but contains UHMWPE fibers (non branded Dyneema) that makes this fabric one of the lightest and toughest in the world (maybe the most).

This “difficult to remember” Ultra-High-Molecular-Weight Polyethylene fiber is 15 times stronger than steel (tensile strenght) and provides an incredible resistance to abrasion and cut.

On the outside Ultra PE fibers blended with hi tenacity Polyester gives strength and resistance, inside a recycled RUV film allows seam taping for waterproofness.

The strongest fabric in the world compared to others in the same weight range, perfect for ultra durable and technical gear, one of the best in this Ultralight Outdoor Fabrics 101 guide.

It has “minor issue” related to aesthetic, the fabric wrinkles really easy, the unused fabric is plain but once you start to cut and sew and fold the RUV film will create permanent lines, when you receive a new piece of gear made with Ultra please don’t complain about creases 🙂

Limited colours: Black, White, Grey and Silverado (a light grey).


Same as Ultra200 but with a 400d face fabric.

If Ultra200 is tough and durable, this version is pretty bombproof!


This is the Challenge Sailcloth answer to the classic 210d Dyneema Gridstop fabric.

Made with strong 100% recycled Nylon and Ultra PE fibers grid, it’s a fabric I love to use in specific parts of a pack (eg. side pockets and shoulder straps).

It’s softer than Ecopak and Ultra and has a tear strength and the PU coating on the inside provides good a weather resistance.

It looks technical because of the grid, you may like it or not but it comes in a variety of colours for every taste.

It’s also a good options if you like softer gear with less stiffness.


This stretch mesh it’s a blend of 6.6 Nylon, Lycra Ultra PE fibers, very strong and reliable compared to classic lycra or spandex but less stretchy overall.

I like to use it on thru-hiking packs or gear that needs more durability, for example is perfect if you like mesh side pockets but you have to bushwhack a lot.

Great option for bottom pocket too or parts where you need a mesh fabric but durability is a concern.

One colour only, one side is grey with white fibers, the other is white with black fibers (sort of).


“Recycled Bag Clothes”, comes in different weight for different applications.

Very similar to classic Cordura, it has a less technical look compared to the other fabric and it’s pleasant to touch.

RBC200 is very light, I use it mostly for lining or internal pockets.

RBC400 is a little bit heavier, I use it to make shoulder straps on the Loop 20L.

RBC 600 is even more heavier, a good option for back panels if you want a better feel on the back.

Challenge Outdoor says: “Each yard recycles about 10 plastic bottles and saves about one pound of carbon emissions, compared to standard nylon or polyester bag fabric.”


Made with 75D polyester and a backing film that can be taped, nice fabric for light and waterproof dry bags or small accessories.

A downside can be the sound, when you open and close a stuff sack it seems you are playing with a bag of chips.

White only and a little translucent.


Spandex/Polyester Mesh

This mesh is very stretchy and pretty durable if you don’t abuse your gear, the go to mesh for the Loop 20L backpack and Mio fanny pack.

I love it on front and side pockets because it can expand a lot and carry a lot of stuff.

A front pocket made with this mesh allows you to carry even a tent!

I found the same mesh in some products made by TNF (big brand acronym).

I use it on my Loop pack, hiking pack and Mio fanny pack, after a prolonged usage I found some minor holes and some wear here and there, by the way, I never had major issues even on bottom pockets.

If you need a more durable mesh check out UltraStretch above.

3D Mesh

This is a classic spacer mesh you find under shoulder straps, I use the 3mm version which is a good balance between weight and cushioning.

I also use it on back panels to create a pocket for your seat pad, also helps a bit with sweat management and comfort.

Ultralight Outdoor Fabrics 101 – Conclusions

I believe the perfect fabric doesn’t exist, as you can see every fabrics has specific characteristics for different applications.

I tested and continue to test different fabrics and materials to provide the right ones for each product I make.

If you have any question feel free to contact me for more info!

For more specs please visit Challenge Outdoors website.