Sea to Summit Ether Light XR sleeping mat | Tested and reviewed

The Sea to Summit Ether Light XR is a sleeping mat that strikes a nice balance between weight, durability, comfort and warmth. An R-value of 4.1 is a solid rating for three-season use, with the internal ThermalCore insulation providing a toasty warmth boost.

Yet the mat is still lightweight and compact, clocking in at 547g (regular version, including storage bag), and packing down to a compact cylinder sized 20x11cm, which is slightly smaller than many competing products.

Sticking with the compromise narrative, the 30-denier and 40-denier nylon materials feel simultaneously lightweight yet reasonably robust, while the slightly-tapered mummy shape is refined for lightness while maximising the mat’s footprint.

The 55cm width and 10cm thickness are particularly impressive, offering extra room and insulation than other brands’ offerings, but the 183cm length is pretty standard. In terms of the sleeping surface, you don’t get horizontal or vertical baffles.

Instead there’s a “quilted” surface with a textured, criss-crossing, grid-like pattern called Air Sprung Cells. This surface may polarise opinion, but we found it very comfortable and cosy (although possibly a bit bobbly).

Inflation and deflation of the Ether Light XR are seamless too, courtesy of Sea to Summit’s high-tech XPRESS valve and Airstream Pump sack. It took us three full sacks of air and barely a minute to fully inflate – efficient stuff.

Comfort

Like Nemo’s Tensor pads, the Ether Light XR features a “quilted” surface rather than the horizontal or vertical baffles found on many pads. This creates a textured, slightly bumpy, grid pattern, sort of like the squares in a maths exercise book turned diagonally by 45 degrees.

I found this to be nicely comfortable, though the surface’s undulating nature definitely felt a little bobbly and uneven under my face (I sleep without a pillow, in case you were wondering – very odd, I know!).

There’s always a comfort payoff when it comes to baffle design and on a scale of 1 to 10, I’d rate it at around an 8 – not perfect, but generally very good. In fact, I’m a little undecided, but I think I find a textured sleeping surface preferable to baffles, and the Ether Light XR is a great version of this approach.

Of course, one person’s dream is another’s nightmare – comfort is subjective. What kind of pad design works for you will be a personal thing, depending on your sleeping position and other preferences. Our advice is always to try a few pads out to get a sense of what works for you.

Materials, shape and size

The Ether Light XR is crafted from a 30 and 40-denier nylon that provides a degree of durability while keeping the overall weight down – a careful balance that every backpacking pad must seek. It’ll put up with the occasional scrape but keep it away from multi-tools and ice axes unless you want a pancake flat pad.

In terms of the Sea to Summit Ether range of mats, there are mummy shaped and rectangular versions available in both the regular and large pads, while the mummy design is the only option when it comes to the small sized pad.

I was testing the regular version, which has a tapered form that strikes a good balance between coverage and packability. The 55cm width is wider than many other mats by a few centimetres, which adds a touch of spaciousness to the sleeping surface, and the 10cm thickness is impressive too.

The Ether Light XR officially measures 183 x 55cm, compared to the 168 x 55cm of the small version – a lighter option for anyone shorter than 165cm (5ft 5”).

The rectangular version and large pads are 64cm wide, while the large pads also cater for taller backpackers, with a 198cm length. All the versions are an impressive four inches (10cm) thick, which provides great clearance above the ground – crucial for effective insulation.

Also available in the Ether range are the Ether Light XT and Ether Light XR Pro. The XT is currently only available in the women’s version and can be picked up for much less than the original RRP of £180. It’s not quite as well insulated as the XR, with an R-value of 3.5, though the regular version is slightly lighter, at 495g.

The Pro version is the best option for year-round camping and, at £245 for the regular size, is currently only £40 pricier than the standard Ether Light XR. It boasts a winter-ready R-value of 7.4 and is only slightly larger when packed down.

The payoff is extra weight, the regular Pro version clocks in at an official weight of 620g, according to Sea to Summit.

Inflation and deflation

The inflation and deflation system is efficient, modern and very clever, similar to that seen on pads like Nemo’s popular Tensor range and Mountain Equipment’s Mirrostat 7.0.

Let’s start with the XPRESS valve, which features two layered caps over one hole. When both caps are fully closed – as you’d imagine – air can’t get in or out.

By removing the top cap, you’re able to inflate the pad but no air will escape (in this orientation it’s a one-way only valve). However, if you deliberately press your finger on the centre of the one-way valve, there’s squidgy, button-like perforation that will sink down and release little bursts of air.

This clever system enables you to micro-adjust the air pressure to your preference. Finally, lifting the bottom cap up is like pulling the plug, opening the entire valve up fully and allowing air to easily escape for relation.

The way the mat’s storage bag doubles up as the Airstream Pump sack is a notable innovation. Sea to Summit has integrated this design into all its Air Sprung Cell mats. One end of the stuff sack opens up to store the pad, while the other unfolds for deployment as the pump.

One breath is enough to fully inflate the sack, while the pad took me three sack-fulls of air to get it nicely inflated. The whole process only took me around a minute.

One advantage of using a pump sack is that less moisture gets in the interior than it would if you were inflating directly from your mouth. Moisture in the pad can lead to mould in the long run.

So, the pump sack is a better solution than blowing the pad up directly, though there’s still some risk of condensation getting in there. However, Sea to Summit have gone further to prevent mould growth, using an anti-microbial treatment to combat the possibility.

Handily, the Airstream Pumpsack is also compatible with the valves on Sea to Summit’s Aeros pillows and its Air Seats.

Having tested several different brands’ versions of pump sacks, I’d say the Sea to Summit version is superior.

It has an excellent design, the sack fills very quickly with minimal breath and the inflation process is very quick, efficient and seamless. The valve is well-engineered and it seems to be bombproof too – I’ve left the mat inflated in my house for several days with not a hint of any air leakage.

Warmth and R-value

R-value is a measure of how well a pad insulates you from the cold ground below. The higher the value, the warmer the mat will be. With an R-value of 4.1, the Ether Light XR is a solid option for 3-season camping and will keep you well insulated even on brisk spring mornings and colder autumn nights.

However, I’d want a higher R-value for winter camping and, at the other end of the spectrum, speedy summer backpacking missions also call for something much lighter. So, the Ether Light XR represents a middle ground that’ll suit most campers.

It achieves its R-value thanks to its Thermal Core insulation, which boasts an infra-red reflecting film that stops heat seeping out due to convection and internal air movement.

Generally, the thicker a sleeping pad is, the better it insulates and the Ether Light XR has a four-inch (10cm) girth, which also helps. This is 1cm to 2cm thicker than many other competitor mats from rival brands.

For some more advice, read our guide on how to keep warm in a tent at night.

Weight and packed size

The Ether Light XR is impressively compact when packed down, easily slotting into any self-respecting wild camper’s backpack.

Sea to Summit has done themselves a disservice by stating an official packed size of 20.5 x 11cm, as my tape measure found that the regular pad was actually 20 x 11cm when packed down – every little helps, right? This is notably more compact than some of its rivals, such as the Exped Ultra 5R (25 x 12cm).

It’s not the lightest pad on the block, but the 547g total weight is pretty impressive considering the 4.1 R-value. This includes the mat (481g), the storage bag with integrated pump sack (56g) and the repair kit (10g).

The warmth-to-weight ratio compares favourably to many of its rivals, though Mountain Equipment has trumped it with its Mirrostat pad, which boasts an R-Value of 4.5 and a total weight of 530g.

The small version of the Ether Light XR is around 25g lighter, but is no more compact. Unsurprisingly the wider rectangular (665g), large (also 665g) and rectangular large (725g) Ether Light XR pads are heavier and not quite as compact – their packed sizes are all in the region of 24 x 12 cm.

So, you’ll have to decide if a larger pad is worth it for the extra weight and decreased packability.

Features

If you’ve got yourself a Sea to Summit Aeros Pillow, you’ll be delighted to know that it’s directly compatible with the Ether Light XR.

The pad comes with self-adhesive hook-and-loop patches (small, curved, sticker-like tabs) that grab hold of the pillow and stop it slipping. Ingeniously, these patches don’t snag other items of clothing either – a really nice touch and a clever solution to an age-old problem.

The bundled in repair kit consists of six self-adhesive patches for quick fixes, as well as a spare valve insert. Hopefully you’ll never have to use them, but they’re certainly handy for peace of mind on committing, multi-day trips.

Verdict

The Sea to Summit Ether Light XR is a top-tier sleeping mat with a 4.1 R-value, superb inflation system and a comfortable “quilted” texture to the sleeping surface – but it’s pricey.

Complete the ultimate camp setup with our lists of the best sleeping bags and the best one-person tents.

About the author

James Forrest writes regular features and route guides for Trail and LFTO, and has been one of our main gear testers for the last few years. James is based on the edge of the Lake District so when he isn’t off on his latest crazy adventure or challenge, he’s walking in his local fells.