Outdoors & Fitness
The Best Guy Lines: 4 Compared (and One to Skip)
Two of these are raw cord you cut and rig yourself, two are finished sets with the hardware already on. That decision matters more than the cord does.
The short version
The Lawson Reflective Glowire is the pick if you are rigging your own: 2mm kernmantle cord with retroreflective tracers braided in, sold by the hank at 57 grams per 50 feet, in a jacket Lawson also uses on its high-strength Ironwire. The Zpacks Z-Line Reflective is the one to take if weight is the point, because 50 feet comes in at a stated 23 grams and it uses 3M Scotchlite tracers over a high-tenacity polyester core, though at 1.3mm Zpacks itself says it suits shorter fixed-length guylines. The Sea to Summit Ground Control Guy Cords suit a specific buyer: a four-pack of finished cords with quick-connect V-toggles and an integrated adjuster, at fixed lengths of two 2.2m and two 1m. Skip the MSR Reflective Utility Cord Kit for most people, because MSR publishes neither a diameter nor a length for it, and in a category where those two numbers are the whole specification that is a lot to take on trust. Best for: campers who would rather buy cord by the metre than inherit whatever came in the bag.
Our picks at a glance
- Lawson Equipment Reflective Glowire Cord - Buy. Two millimetre kernmantle cord with retroreflective tracers braided into the jacket, sold by the hank so you rig it to your own shelter.
- Zpacks Z-Line Reflective Cord, 1.3mm - Buy. Fifty feet for a stated 23 grams, with 3M Scotchlite tracers, and a maker honest enough to tell you what the diameter is not good for.
- Sea to Summit Ground Control Guy Cords, 4 Pack - It depends. A finished four-pack with quick-connect toggles and built-in adjusters, at fixed lengths chosen for Sea to Summit's own tents.
- MSR Reflective Utility Cord Kit - Skip. A reflective knot-free cord kit from a maker that normally publishes everything, and here publishes almost nothing.
The verdict in 30 seconds
What mattered most
- Raw cord or finished set
- Stated diameter
- Stated weight
- Lengths offered
- Reflective element
- Construction stated
Guy line is the cheapest thing holding your shelter up and the part most people inherit rather than choose. The category splits in two before you get anywhere near the specification. You can buy cord on a hank, cut it to length and add your own adjusters, or you can buy a finished set with fixed lengths and the hardware attached. The first is cheaper per foot and fits any shelter; the second removes the knot-tying and is sized for somebody else's tent. We took two of each and read what the makers publish.
Two millimetre kernmantle cord with retroreflective tracers braided into the jacket, sold by the hank so you rig it to your own shelter.
Best for: Anyone rigging their own shelter who wants one cord that suits tents, tarps and awnings alike.
- 2mm diameter, which is the usual size for tent and tarp guy-outs on anything larger than an ultralight shelter.
- Reflective tracers work like a road sign, throwing light straight back at a headlamp, so the brighter the beam the more the line shows up.
- Lawson states it now uses the UltraFuzion jacket, the same jacket it has used on its Ironwire cord for years.
- Sold in 50 foot and 100 foot hanks and a 500 foot spool, at a stated 57 grams per 50 feet, in six colours.
- Braided in house on Lawson's own machines, which is why the construction detail is on the page at all.
- You supply the adjusters and tie the knots, so the finished cost is higher than the cord price suggests.
- At 2mm it is heavier than the ultralight cords, which matters if you are guying out a tarp for a thru-hike.
- No published breaking strength on the product page.
- Cutting from a hank means sealing the ends yourself or watching them fray.
Fifty feet for a stated 23 grams, with 3M Scotchlite tracers, and a maker honest enough to tell you what the diameter is not good for.
Best for: Ultralight shelters with short fixed guylines where 23 grams against 57 is worth the handling penalty.
- Zpacks states 50 feet at 23 grams in the 1.3mm size, which is the lightest figure published here by a wide margin.
- Reflective tracers are 3M Scotchlite, named rather than described generically.
- Abrasion and UV resistant polyester jacket over a high-tenacity polyester core, so it resists both sun and stretch.
- Zpacks says it is tangle resistant, which is a real property of a stiff thin cord and a genuine annoyance in the ones that are not.
- Sold alongside Micro Linelocs and Lineloc V adjusters from the same maker, so the hardware question has an answer.
- Zpacks states outright that 1.3mm suits shorter fixed-length guylines, so it is the wrong choice for long tarp guy-outs.
- Thin cord is harder on the hands when you are tensioning in the cold.
- One diameter and one length per listing, with no hank or spool option.
- No published breaking strength.
A finished four-pack with quick-connect toggles and built-in adjusters, at fixed lengths chosen for Sea to Summit's own tents.
Best for: Owners of Sea to Summit Alto or Telos tents, and anyone who wants guy lines that work without learning a knot.
- Quick-connect V-toggles that Sea to Summit says eliminate the need for knots entirely.
- An integrated adjuster on each cord, so tensioning is a slide rather than a taut-line hitch.
- Reflective, which Sea to Summit frames as much about not tripping over them as about finding the tent.
- The set is two 2.2m and two 1m cords at a stated 36 grams, and cords can be joined together for extra length.
- Supplied as standard with the Alto and Telos tents, so they are a known quantity with that hardware.
- Fixed lengths sized for particular tents, so they may be too short or long for yours.
- The V-toggles need a compatible guy-out point to connect to.
- No published cord diameter, which makes it hard to compare against cord sold by the metre.
- Four cords is fewer than a well-guyed shelter needs in wind.
A reflective knot-free cord kit from a maker that normally publishes everything, and here publishes almost nothing.
Best for: Replacing a lost guy line on an MSR tent where the original length is already known.
- Reflective cord supplied with adjusters, so the kit works out of the packet.
- MSR describes it as knot-free, which is the useful property of a kit over raw cord.
- Cheapest option here, and it comes from a maker whose stakes and shelters are widely trusted.
- No published cord diameter, which is the single most useful number in this category.
- No published length, so you cannot tell whether the kit will reach your guy-out points.
- No published weight either, which is unusual for MSR and makes it impossible to compare against the 23 and 57 gram figures the others give.
- The product description on MSR's own page runs to five words.
| Criteria | Reflective Glowire Cord | Z-Line Reflective Cord, 1.3mm | Ground Control Guy Cords, 4 Pack | Reflective Utility Cord Kit |
|---|---|---|---|---|
| Verdict | Buy it | Buy it | It depends | Skip it |
| Best for | Anyone rigging their own shelter who wants one cord that suits tents, tarps and awnings alike. | Ultralight shelters with short fixed guylines where 23 grams against 57 is worth the handling penalty. | Owners of Sea to Summit Alto or Telos tents, and anyone who wants guy lines that work without learning a knot. | Replacing a lost guy line on an MSR tent where the original length is already known. |
| Price tier | $$ · mid-range | $$ · mid-range | $$ · mid-range | $ · budget |
| Raw cord or finished set | Raw cord, sold by the hank | Raw cord, sold by the length | Finished set of four cords | Finished kit with adjusters |
| Stated diameter | 2mm | 1.3mm | Not published | Not published |
| Stated weight | 57g per 50 feet | 23g per 50 feet | 36g for the four-cord set | Not published |
| Lengths offered | 50ft and 100ft hanks, 500ft spool | 50 feet | Two at 2.2m and two at 1m | Not published |
| Reflective element | Tracers braided into the jacket | 3M Scotchlite tracers | Reflective cord | Reflective cord |
| Construction stated | Kernmantle, UltraFuzion jacket | Polyester jacket over high-tenacity polyester core | Not published | Not published |
| Adjuster included | No, you add your own | No, sold alongside Micro Linelocs | Yes, integrated on each cord | Yes |
| Knots needed | Yes | Yes | No, quick-connect V-toggles | No, described as knot-free |
| Maker's own caveat | None stated | Suits shorter fixed-length guylines | Sized for Alto and Telos tents | None stated |
Which one is right for you?
- Anyone rigging their own shelter who wants one cord that suits tents, tarps and awnings alike. Buy it Lawson Equipment Reflective Glowire Cord
- Ultralight shelters with short fixed guylines where 23 grams against 57 is worth the handling penalty. Buy it Zpacks Z-Line Reflective Cord, 1.3mm
- Owners of Sea to Summit Alto or Telos tents, and anyone who wants guy lines that work without learning a knot. It depends Sea to Summit Ground Control Guy Cords, 4 Pack
- Replacing a lost guy line on an MSR tent where the original length is already known. Skip it MSR Reflective Utility Cord Kit
How we judged the field
Five things decide a guy line and the first is not the cord at all. It is whether you are buying raw cord or a finished set, because that determines whether you can cut it to your shelter or have to live with somebody else’s lengths. The second is diameter, which sets how the cord handles in the cold and how much load it will take. The third is weight, which is the price of that diameter and the reason the ultralight cords exist. The fourth is how the reflective element is made, because tracers braided into a jacket last and a printed coating does not. The fifth is what the cord expects you to do about tension: tie a knot, add your own adjuster, or use hardware that came attached.
The field splits cleanly along the first of those, so we took two from each side. Lawson and Zpacks sell cord, with the diameter and the weight per length printed on the page, and leave the hardware and the cutting to you. Sea to Summit and MSR sell finished kits, with adjusters and toggles included and the cutting already done. That difference turns out to track the disclosure too: both of the cord makers publish a diameter and a weight, and neither of the kit makers publishes a diameter at all. Sea to Summit at least states the four lengths in its set and the weight of the set. MSR publishes neither, which is what puts it at the bottom of this comparison.
Lawson Equipment Reflective Glowire Cord - buy
The Glowire is the cord we would buy for a shelter we intended to keep. Lawson sells it at 2mm, which is the diameter that suits most tents and tarps, on hanks of 50 and 100 feet and a 500 foot spool, at a stated 57 grams per 50 feet. The reflective element is the interesting part: the tracers are braided into the jacket rather than applied to the surface, and Lawson describes them working like a road sign, so the brighter the light you shine the more the cord throws back. That is retroreflection rather than a glow, and it is the property that makes a guy line visible from across a campsite. Lawson has also moved the cord onto its UltraFuzion jacket, the same one it has used on Ironwire for years, and says it braids in house on its own machines, which is why there is construction detail on the page at all. The costs are honest ones. You buy adjusters separately, you tie your own knots, and at 2mm it is the heaviest cord here.
Zpacks Z-Line Reflective Cord, 1.3mm - buy
The Z-Line is the ultralight answer and the one whose page tells you where not to use it. Zpacks states 50 feet at 23 grams in the 1.3mm size, less than half the Lawson figure, with 3M Scotchlite tracers named specifically rather than described as reflective. The construction is an abrasion and UV resistant polyester jacket over a high-tenacity polyester core, which addresses the two things that actually kill guy line: sunlight and stretch. Zpacks also says it is tangle resistant, which sounds like filler until you have spent five minutes in the rain unpicking a thin cord. What makes this listing better than most is the caveat: Zpacks writes that the 1.3mm size is better for shorter fixed-length guylines, which is the maker telling you its own product has a range. Pair it with the Micro Linelocs from the same shop and you have a complete system; buy it for long tarp runs and you have bought the wrong diameter.
Sea to Summit Ground Control Guy Cords, 4 Pack - it depends
The Ground Control cords are the finished option done properly, within limits they are open about. The set is four cords, two at 2.2m and two at 1m, at a stated 36 grams, each with an integrated adjuster so tensioning is a slide rather than a knot. The distinctive part is the quick-connect V-toggle, which Sea to Summit says removes the need for knots entirely, and cords can be joined to one another when you need a longer run. They ship as standard with the Alto and Telos tents, and that is the clue to who should buy them: the lengths were chosen for those shelters. On a different tent you may find the 1m cords reach nothing useful. There is also no published diameter, so you cannot line them up against cord sold by the metre, and four cords is fewer than a shelter needs when you are guying it out properly against wind rather than adding a couple of lines for tidiness.
MSR Reflective Utility Cord Kit - skip
The Reflective Utility Cord Kit is the one we would leave, and the reason is what is missing rather than anything it does wrong. MSR is normally among the better companies in this category for published specification: its tent stakes carry a weight in grams, a length in centimetres and a named ground type. This product gets a five word description, no diameter, no length and no weight. In a category where diameter and length are the entire specification, that leaves you unable to answer the two questions that matter before buying: will this cord handle in the cold, and will it reach my guy-out points. The kit itself is reflective and comes with adjusters, which is the right idea, and as a like-for-like replacement on an MSR tent whose original lengths you already know it is perfectly sensible. As a general purchase it asks for more trust than the page earns.
Lawson Equipment Reflective Glowire Cord vs Zpacks Z-Line Reflective Cord, 1.3mm: which should you buy?
The Glowire and the Z-Line are the two to choose between, and the question is the length of your guy-outs rather than your taste in cord. Lawson’s 2mm at 57 grams per 50 feet is the general answer: it handles well in cold hands, it suits a tarp run as readily as a tent guy-out, and it comes on a hank so you cut what the shelter needs. Zpacks’ 1.3mm at 23 grams per 50 feet is less than half the weight, and Zpacks is clear that it earns that on shorter fixed lengths.
The other difference is what surrounds the cord. Lawson publishes its construction, its jacket and its colour range, and expects you to bring your own hardware. Zpacks sells Micro Linelocs and Lineloc V adjusters from the same shop, so the system is already assembled if you want it. Both use reflective tracers rather than a coating, though only Zpacks names the material. If you own one shelter and want one cord for it, buy the Lawson by the hank. If you are counting grams on a shelter with short guylines and already own linelocs, the Z-Line is the better fit and the lighter one.
What to look for
- Decide raw cord or finished set first: it governs whether you can match the lengths to your shelter or have to live with somebody else’s.
- Look for a diameter in millimetres: 2mm suits most shelters, and anything near 1.3mm is an ultralight choice with handling costs.
- Check weight per length, not per item: 23 grams and 57 grams per 50 feet is the real comparison, and a set weight tells you nothing about cost per metre.
- Prefer tracers braided into the jacket: a reflective coating wears off, and only some makers say which they used.
- Budget for adjusters if you are buying cord: a hank plus a set of linelocs is a different price from the hank alone.
- Count your guy-out points before you buy a set: four fixed cords rarely covers a shelter you are actually trying to hold down in wind.
Our final take
Guy line is bought once and cursed at three in the morning, which is a good argument for spending a few minutes on it. The split that matters is between cord and kit, and the disclosure follows that split almost perfectly: the two makers selling cord both publish a diameter and a weight per length, and the two selling finished kits publish neither diameter. Lawson’s Glowire at 2mm is the sensible default, sold by the hank so it fits your shelter rather than somebody else’s. Zpacks’ Z-Line is the right call when grams matter and the runs are short, and the page is honest about that limit. And a utility cord kit with no diameter, no length and no weight is asking you to buy on the badge.
Questions, answered
What diameter guy line should I actually buy?
For a general tent or tarp, 2mm is the usual answer and it is what Lawson sells the Glowire in. It is thick enough to grip and tension by hand in the cold, and strong enough for a shelter that catches wind. Ultralight cords around 1.3mm exist to save weight on short runs, and Zpacks is straightforward that its 1.3mm size suits shorter fixed-length guylines. Below about 2mm you gain grams and lose handling. If you only buy one cord, buy 2mm.
Is reflective cord worth paying for?
Yes, and not mainly for finding your tent. The common accident is walking into a guy line in the dark, which at best pulls a stake and at worst takes the shelter down with somebody in it. Reflective tracers throw a headlamp beam straight back at you from several metres away. The distinction worth knowing is between tracers braided into the jacket, as on the Lawson and Zpacks cords, and a reflective coating, which wears off. Sea to Summit frames its reflective cords explicitly around not tripping over them.
Do I need line adjusters, or will a knot do?
A taut-line hitch works and costs nothing, and plenty of people never use anything else. Adjusters earn their place in two situations: when you are retensioning in the middle of a wet night, and when your hands are too cold to tie anything. The finished sets here include them, Zpacks sells Micro Linelocs to go with its cord, and with the Lawson hank you are buying them separately. Factor that into the price, because a hank of cord plus a set of linelocs is not the cheap option it first appears.
How much guy line do I need for a tent?
More than the two or three cords most tents ship with. Count your shelter's guy-out points, including the ones on the fly you have never used, and allow roughly two to three metres each for a tent and rather more for a tarp, which needs longer runs to reach anchors. That is where buying by the hank wins: a 50 foot hank covers a tent with spare, and a 100 foot hank covers a tarp setup. A four-pack of fixed-length cords does not stretch to cover a shelter you have to guy out properly in wind.
Why do some makers not publish a diameter?
Because a finished kit is sold as a solution rather than as cord, so the marketing focus moves to the toggle or the adjuster. That is fair enough for a set matched to the maker's own tent, which is what Sea to Summit is doing with the Ground Control cords. It is less defensible on a general utility kit, and MSR's Reflective Utility Cord Kit publishes neither diameter, length nor weight, which leaves you unable to check whether it will reach your guy-out points before it arrives.
Deciding between the top two? See our head-to-head: Lawson Equipment Reflective Glowire Cord vs Zpacks Z-Line Reflective Cord, 1.3mm.
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