All About Slackline Webbing

In the Balance Community Shop, there are a number of different slackline webbing's to choose from. Each of these webbing's is unique in it's own right and each have special characteristics that are favorable for certain types of slacklines and slackliners. I would like to take a look at the characteristics in detail to help people decide which webbing is right for them.

First off, there are a number of characteristics that are similar across all slackline webbings that can be used to compare two webbings very easily. Here is a list of these properties:

1. Breaking Strength
2. Stretch
3. Weight
4. Thickness
5. Hand

I will go into detail about each of these below:

Breaking Strength

The breaking strength of a webbing is a very important property as it defines (in combination with stretch) how safe a webbing is for use in slacklines (specifically, highlines). The stronger your webbing, the safer it will be. There is a good rule of thumb to go by and that is to make sure your webbing is at least 3 times stronger than the maximum tension you will ever tension said webbing to. For instance, if you plan on setting up a line that is 600 feet long with about 8 feet of sag, that will require roughly 3,000 lbs of tension. This means you should not use a webbing that breaks at a force lower than 9,000 lbs.

Be very careful with the strength of webbing though, there are many things to take into consideration. The most important is the safety cushion that is placed on the strength rating of the webbing. Typically, webbing's made in the US are rated very conservatively in order to protect the mills that produce them. This is because there are such large fluctations in the finished product. The process of milling a webbing allows for many things to go wrong, such as the width of the webbing, the tensions of the individual monofilaments, the tightness of the weave. Also, other things can happen during the weave that can affect the strength of the finished substrate. These include broken monofilaments, miss-weaves, loose fiber ends, and a few others. All of these combined can allow for HUGE ranges in the breaking strength for webbing, even within batches from the same manufacturer. This is why it's important to not read too heavily into the breaking strength numbers for all webbing. As I said before, webbing in the US tends to have a large cushion placed on the breaking strength for this reason. Webbing made in other parts of the world does not usually have these kinds of safety margins, which is why it's important to look at how the company that sells the webbing is rating their material.

The strength is not the only factor to look at when considering the safety of a webbing. The stretch plays a VERY large roll in how safe your line will be, which we will be looking at next.

Stretch

The stretch of your webbing plays a very important roll in how safe your line is for highline use. The higher the stretch of your line, the less strong it needs to be. The reason for this is because during a leash fall your line will be shockloaded by the impact force of your fall. In a low stretch webbing, the fall happens very quickly, which results in a high impact force, thus higher shockload values occur. On a high stretch webbing, the leash fall happens a lot slower. This is becase the webbing is stretching as you are falling, which lengths the time for the impact force to peak. The slower the fall, the lower the impact force, the lower the shockload on your webbing. So high stretch webbings experience lower shockload values compared to low stretch webbings. This is why the lower the stretch of your webbing, the higher the strength needs to be. This isn't to say that low stretch webbings are unsafe for highlines though, it just means that you should use only the highest strength materials if you choose to go the low stretch route (i.e. Mantra and Spider Silk MKII).

Not only is stretch an important factor in highline safety, but it's also a characteristic of highly dynamic webbing. High stretch webbings lend themselves to more dynamic tricks on the slackline. For instance, surfing and bouncing the line become much more powerful on a stretchy webbing compared to low-stretch lines. If you like dynamic slacklines, then high stretch webbing is definitely for you (i.e. Type-18 and Threaded Slack-Spec Tubular).

Stretch also plays a big roll in how easy your line will be to setup. A webbing with higher stretch will need to have more slack pulled out of it to get to walking tension compared to a low-stretch webbing. More slack being pulled out means more work, and more rope for your Pulley System, which means less energy for walking. If you are into quick setup times, then low stretch webbing is for you (i.e. Mantra and Spider Silk MKII).

Weight

The weight of your line (combined with the stretch) determines how difficult it will be to walk. A lighter webbing will always be easier to walk than a heavier line. This is because there is more weight to react to your movements when walking the line, which in-turn have more momentum that has the potential to throw you off the line.

Thickness

The thickness of your webbing is mainly important for locking devices as well as how sharp the line is for catching on a highline. Thicker webbing's tend to not do as well as thinner webbing's in webbing anchors. This is because when a thick webbing bends around a radius, the inside fibers are stretching much less than the outer fibers (depending on the size of the radius), resulting in low breaking numbers. The thickness is not the only factor that determines this though, stretch plays a large part in this.

Also, for catching on a highline, a thicker webbing is usually far less sharp than a thin webbing. This is wonderful if you take a lot of falls on highlines and don't want to get scrapped up too badly.

Hand

The hand of a webbing is basically how it feels in your hands and on your feet. Some webbing is soft, some is stiff, some has ridges, and some is very rough. There are many variables that determine how the webbing feels, all of which effect the other characteristics above. Each individal webbing has a different hand, so I will describe the features that effect each webbing below.

That concludes the description part of this articles, now onto individual analysis of the webbing's offered in the BC Shop:

1" Threaded Slack-Spec Tubular

• Breaking Strength: Roughly 7,000 lbf. Hard to tell as there are two lines which share the total tension in various amounts.
• Stretch: 13.5% at 2,000 lbf
• Weight: 70 grams/meter (4.7 lbs/100 ft.)
• Thickness: 0.157" (4.0 mm)
• Hand: Extremely Soft

Threaded Slack-Spec tubular is one of the classic slackline webbings. It's been around since the beginning and it's still one of the best webbings out there for slacklining. The high stretch allows for some amazing dynamic movements, even on shorter lines. It's one of my favorite webbings for lines under 150 ft. long as well as a really fun longer line webbing (250-350 feet). The thickness makes for a great highline webbing because it's very soft on your hands for catching. The high stretch also lends itself to soft falls on a highline. Beware of the rattle sounds that threaded tubular makes though. The inner line moves when the line shakes, which causes a rattling-like sound, which is unique to threaded-tubular.

The extremely soft hand is mainly due to the size of the nylon fibers used in the weave. The monofilaments are 840 denier, which refers to the weight (and diameter). This is much smaller than most other webbing's, which is why it's so silky smooth.

Type-18

• Breaking Strength: 6,000 lbf. (26.7 kN)
• Stretch: 13.9% at 2,000 lbf
• Weight: 60 grams/meter (4.0 lbs/100 ft.)
• Thickness: 0.118" (3.0 mm)
• Hand: Extremely Soft

Type-18 is a very nice webbing for all sorts of lines. It's definitely the most versatile webbing out there. The high stretch makes it great for shorter trick-style lines, as well as highly dynamic longlines. You can also wrench it down pretty tight for a fun-to-walk longer line. The high stretch also makes for very comfortable highline falls. It's quite thick as well for not so sharp highline catches. I really like Type-18 in the 250-350 ft. range for it's amazingly powerful bouncing and surfing sensations. No other webbing out there has the same power that Type-18 has.

The extremely soft hand is mainly due to the size of the nylon fibers used in the weave. The monofilaments are 840 denier, which refers to the weight (and diameter). This is much smaller than most other webbing's, which is why it's so silky smooth. It's also woven with a twill weave and a reversal, which makes it a bit stiffer than Threaded Slack-Spec Tubular, but still soft.

Mantra

• Breaking Strength: 9,450 lbf (42.0 kN)
• Stretch: 3.1% at 2,000 lbf
• Weight: 72 grams/meter (4.8 lbs/100 ft.)
• Thickness: 0.106" (2.7 mm)
• Hand: Soft with ridges. Also a little stiff.

Mantra is a very powerful polyester webbing with amazingly low stretch. It's very easy to rig even super longlines with Mantra because of it's low stretch. You can also get it VERY tight for some really long tricklines. I really like Mantra in the 600-700 foot range as the movements are very very slow and allow for a really relaxing longline walk. Bouncing Mantra at these lengths is fantastic too because of how slow the movements are. On lines in the 250-350 foot range, Mantra behaves very nicely. The slow movements give you a lot of time to react and correct yourself, which makes for a very pleasant walk.

The soft hand and ridges of Mantra are due to it's tubular weave and fiber size. The monofilments are 3200 denier, which is significantly larger than most webbing's out there. This gives the webbing ridges, which add to the grip of the line. The stiffness is due to the binder fibers which close the tubular shape that initially woven into Mantra. These are fibers that go from the top of the webbing to the bottom. It makes the webbing quite a bit more stable (stays flat) under tension compared to other webbing's.

Spider Silk MKII

• Breaking Strength: 14,000 lbf (62.3 kN)
• Stretch: 2.1% at 2,000 lbf
• Weight: 49 grams/meter (3.3 lbs/100 ft.)
• Thickness: 0.1001" (2.555 mm)
• Hand: Strong, stiff, and smooth

Spider Silk MKII is the most advanced slackline webbing on the planet. By far the strongest 1" webbing on the market, as well as the lowest stretch. These two features alone make Spider Silk MKII the best webbing out there for large lines (300 feet and beyond). The very low weight makes for a very pleasant walk on even the longest of lines. My favorite length with Spider Silk MKII is in the 800 - 1000 foot range. The bounces and walking is so incredibly smooth, it's unreal. It's a bit on the thin side for highline catches, but this can be solved by doubling it up, which is the optimal rig for any long highline (longer than 150 feet).

The strong and stiff feelings of this webbing comem from the resin coating that is applied post weaving. This coating binds the fibers together very tightly making the webbing feel like a solid object rather than a woven substrate. The smooth feeling come from the twill weave and the 2-ply, 1500 denier monofilments. This weave style also makes for a very stable platform under tension.

Here's a nice table showing the differences between the four webbing types above:

Here is a chart that displays the stretch of each of the above webbing's compared to the force (in Kilo Newtons).

This concludes this article on webbing characteristics. Stay tuned for more articles on different products in the near future.