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Brooks Range Mountaineering Ultralite Guide+Tarp

Square Holden Pitch
Square Holden Pitch

I like square flat tarps because they give me the opportunity to select or create different pitches depending on my environmental needs or aesthetic desires for the night. It’s like shelter origami ( see Square Tarp Pitches.)

Contrary to what you might expect, there’s a lot of variation in square tarp design, size, materials and weight/function trade-offs. Flat tarps come in different fabrics such as silnylon, heavier poly-urethane coated nylon, and ultralight cuben fiber. Many have tie-outs in different places along the perimeter of the tarp or on inside diagonals that can make certain shapes easier to pitch than others. Some tarps are cut from a single piece of fabric and others have ridgeline seams. Some seams need to be sealed and others are taped or bonded and need no at-home finishing before use. There are many other design nuances that can make a tarp easier to pitch  and more adaptable.

Velcro perimeter enables closed A-frame sides
Velcro perimeter enables closed A-frame sides

Ultralight Guide + Tarp Features

Brooks Range Mountaineering sells a variety of flat and shaped tarps in different sizes. Some of their stuff is downright odd, but that’s because it’s designed for mountaineering, backcountry skiing, and winter search and rescue, so we need to make for allowances. :-)

The Ultralight Guide+Tarp is designed as a flat tarp with some additional safety features in mind. I got the 10′ x 10′ model which is rather large for a single person, unless you like to use pitches like the Square Holden (top)  where the tarp serves double duty as a shelter and a ground cloth.

For tie-outs, the tarp has four in the corners and an additional five on each side, which provide a lot of flexibility for pitching the tarp in origami variants or around different environmental features like trees, fallen logs, and rocks as wind/rain breaks. There’s also a piece of fabric sewn into the very center of the tarp over the ridgeline  that can be used for suspending the tarp from a tree or as a ground level tie-out. Notably absent for a tarp of this size are any diagonal tie-outs which can be used to pull out the tarp fabric and increase interior room, as well as set up other types of low-to-the-ground bad weather pitches.

There’s also a ridgeline down the middle, sewn using a french seam for durability and water resistance, though I would still recommend seam sealing it

Floor is attached to walls using velcro permieter
Floor is attached to walls using velcro perimeter

Unique to this tarp, there’s a line of velcro running around there entire perimeter of the tarp border. I believe the main intent behind the velcro perimeter is to enable the tarp to be used as an emergency bivy or human burrito wrap for hypothermia injuries, but tarps are perfectly suited for this task already without velcro. Regardless, the velcro enables some interesting pitching options that are difficult to pull off without it, such as the ability to make end doors to keep out weather or to seal the outer walls to the floor in pitches where you use the tarp body as a ground cloth.

Calendared Fabric

Although it looks like a silnylon camo tarp, the BRM Ultralight Guide+Tarp is made using a different fabric preparation process known as calendaring. Here’s how Brooks Range Mountaineering describes it:

“Our ultralight hi-tech fabric, Intrepid®, is a 20/20 denier ripstop nylon fabric, and is only available with Brooks-Range UltraLite™ products. It does not rely on coating or impregnation by either polyurethane or silicone to achieve waterproofness. Instead it has a cire finish produced by subjecting the fabric to calendering. Calendering is a heat and pressure finishing process that irons the fabric flat with heated rollers so the yarns bond together, converting the loose woven mesh into an integrated fabric that is smooth, water tight, incredibly strong and resilient for its ultra light weight.”

I’m not familiar with this calendared fabric or how well it retains its waterproofness after multiple compression cycles.  BRM claims it is waterproof to 1 PSI but I’m not sure how to convert that into the metric measurements used by other testers. If you do know, can you leave a comment?

Quality Issues

I always test gear close to home before I field test it on the planned hikes and backpacking trips that I write trip reports about. I don’t like leaving anything to chance. This proved to be a useful precaution with this tarp.

Torn Center Guy-out
Torn Center Guy-out

First: the tie-out above the ridgeline on the center of the tarp tore out. Unlike the webbing tie-outs that are double-tacked on the perimeter of the tarp, the center tie-out is a piece of calendared camo sewn into the top of the tarp, straddling the ridgeline. It fell apart out in a low tension configuration creating a thread hole along the ridgeline that must be seal-sealed. It didn’t take much, so be forewarned.

Second: in the process of pitching the Ultralight Guide+Tarp, I noticed that my pitches were not lining up symmetrically and had more sag than I’d expect in a square tarp. Square tarp pitches relay on symmetry between side length and tie-outs to get taught, wind resistant pitches.

When I got home, I got out my ruler and did some measuring to see if the tie-outs had been sewn symmetrically. Unfortunately the distances between them vary by as much as 5 centimeters on opposite sides of the tarp. Further the sides of the tarp are not 10′ square but closer to 9′ 7″ square. These measurement discrepancies don’t make the tarp completely unusable, because you can still pitch it in an A-frame configuration from the ridgeline, but they make it difficult to use if you rely on squareness and symmetry for your pitches.

Third: The weight of the tarp I tested is 16.5 ounces, while the listed manufacturer weight is 15.4 ounces. This is doubly surprising  since my tarp is “small.”

A-frame with a back wall
A-frame with a back wall


The manufacturing and measurement inconsistencies on this tarp compromise its utility for me as a truly square tarp. I have to say I’m really disappointed because the velcro perimeter has some interesting applications in difficult pitches and I love the camo color. I wish I had the time to field test a replacement, but that’s unlikely to happen this year. On the other hand, if you only plan on pitching this tarp in an A-frame style pitch between two trees or from a ridgeline, then it might work perfectly well for you. A little seam sealing, and this tarp will make a good multi-person tarp or dining fly.

Disclosure: Brooks Range Mountaineering provided Philip Werner ( with a tarp for this review. 

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  1. I use quite a bit. You can find the PSI-to-whatever conversion under the “Pressure” category. In this case, it looks like 1 PSI is equal to 703 mm h2o.

  2. I just read the product description on the website. Brooks-Range says that 1 PSI is “more than the pressure generated by a hard rainstorm.” However I just read an article on REI’s website that says wind-driven rain is approx. 2 PSI. So I guess it might be okay repelling a general rain storm but I can’t imagine it would stay dry in a hard rain, or if you were using part of it as a ground cloth in a pitch like the Square Holden. I think silnylon has a rating of at least 1,000 mm h2o in which case makes it more water resistant than the material on this tarp.

    • I think it depends on the denier (thickness of the silnylon) hard to make an apples to apple comparison without that, but yes, overall I think this fabric is probably better for snow than rain.

  3. seems like for the price you should be getting a higher quality tarp. All the more reason for me to stick to the cheap egret i have.

  4. Sounds like this one has a lot of issues especially for the price of it. The velcro does sound nice though.

  5. Looks pretty versatile with all the ways you set it up. Bummer about the quality issues. Thanks for sharing the results.

  6. Thanks for this great write up, this looks like a potentially awesome shelter option. The camo is great for stealth camping, the velcro might help keep some fire ants out. What a shame about the negatives you found, I was excited when I finally found this one! Suppose the search is still on….

    • I had a very specific use in mind that required a perfectly square tarp and symmetrical tie-outs – it’s still a nice tarp for less exacting uses. I also it’s safe to say that they are looking carefully at their current products to make sure the sewing is a bit more precise. I heard my review got sent up the ladder pretty quick. This is a brand I’ve had multiple contacts with over the years and I respect a lot of the other gear they produce, especially their snow science tools and jackets.

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