Marking the Middle of a Rope

I have been entertaining the idea of putting a middle mark on my new light-green rope, but don’t want to use something that will damage it. I’m thinking of using red food coloring, which I think is water based. Would this be safe to use on my rope?

—Harriman via rockandice.com

Knowing when you are halfway done with anything is valuable information. Imagine driving a car without a fuel gauge. I’m stumped as to why some ropes still don’t have middle marks, and the question of how to mark the middle of a rope is among the most frequently asked here. Knowing where the middle of your rope lies is a SAFETY ISSUE. You need the mark for rigging the rope for rappels and especially for knowing whether you can lower from an anchor. By gum, you even need it for coiling the rope.

But we will deal. The quick answer to your question is “probably.” There are many red food colorings and dyes, the most popular being Red No. 40, which is a petroleum extract and a dye, and another is carmine, which is coloring made from boiled insects such as the cochineal beetle, and is used to perk up the colors of foodstuffs such as yogurt, ice cream and juice. That’s right, maggot, you eat mashed bugs nearly every day.

Dyes and colorings used for food might be fine for nylon, but they have not been tested, and would certainly be messy. There are options.

First, though, consider that the UIAA safety commission advised against homemade rope markings after ropes marked with felt-tipped pens held only half as many falls.

Yikes, but in the real world the UIAA warning isn’t especially relevant since to replicate their results you would have to repeatedly fall exactly with that middle marking over an edge or carabiner, and take the savage factor-two fall used in the tests. Then consider that tensile tests on ropes marked with a Sharpie, done by Kolin Powick and crew at Black Diamond, showed that marked ropes still broke at the knot, proving, again, that your tie-in knot is your rope’s weakest point, emphasizing the importance of keeping the ends of your rope in good condition.

As you can see, contradictions abound in the world of marking ropes. Fortunately, as usual, Gear Guy can settle this once and for all: Instead of using some suspect food dye or a pen that may or may not cause your rope to break, buy and use the Beal Rope Marker. This $10 bottle of elixir, available from REI, has, according to REI, been tested and proven safe on Beal, Blue Water, Edelweiss, Lanex, Maxim, PMI and Roca ropes.

Oops, wait a minute. Tests conducted by Mammut, using the Beal Rope Marker on their ropes, showed a decrease in strength by 50 percent for their non-dry ropes and a decrease of 17 percent for their dry ropes. What a cluster! My recommendation is not to mark your rope with anything. Instead, flake the rope from the ends and arrive at the middle, and always knot the free ends to prevent rappelling or being lowered off them. Next!

This article appeared in Rock and Ice issue 199 (January 2012).