I was reading this question and the first thing that popped into my head is what do you use to mark the middle of the rope?

I was taught not to use any kind of marker on the rope (because there's no sure way to know it wont be abrasive). Are there safe ways to mark a rope?

Related: Safe Way to Mark a Carabiner.

7 Answers 7


You can buy specialist markers.

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They're designed to not impact the rope strength. Always use a specially designed rope marker as there is a comprehensive list of things to keep away from your rope and marker pen is one of them. The solvents can break down the nylon rope fibres making your rope potentially unsafe.


No matter what, try not to use the spray-paints at all. Considering that fact that most of the spraypaint and allied products contain solvents/chemicals like CCl4, Acetone, Methyl ethyl ketone, Ethylbenzene, Butoxyethanol and Xylene, etc. If I were you, I would not use it on my ropes for that matter.

  1. Dedicated Rope Markers : Spend some bucks and get a rope marker which is specifically engineered for this purpose.

  2. Worst case you might use the dental floss by simply stitching it into the sheath. All you have to do is get a sewing needle with dental floss. Thread/Sew/Work the dental floss around the middle of the rope, making sure that its through the rope's sheath and not through the core. Repeat the same till you find the mark large enough to spot. But this is advised only if you know how to do it, else you will end up killing the strength of the rope by tampering it's core. Guidance highly recommended.

  3. Marking the rope with a tape: I have seen some climbers, typically beginners that they use a Duct-tape or electrical tape and wrap it around the point where you want mark it. This works fine for an event/session or so, but as after a few passes through descenders and carabiners and other equipment, the tape goes. But this works for a day or two. And, I personally that it should to be removed when you are done for the day as you never know how does the adhesive in the electrical or duct-tape react over longer times. Having said the above, one should also consider that the tape can come loose over the time and use and obviously shift its position.

  • 6
    I'm not 100% convinced by the dental floss idea. This seems dangerous. It would be easy to compromise the integrity of the sheath, this accounts for a significant amount of the strength of the rope so be careful with this.
    – user2766
    Commented Aug 26, 2014 at 14:34
  • Is the glue on electrical tape (or duct-tape) safe for the rope?
    – Roflo
    Commented Aug 26, 2014 at 17:56
  • 1
    @Roflo depends upon what sort of a tape we are referring to and how prolonged its used. The answer suggests that one should get rid of the tape after the day's work
    – WedaPashi
    Commented Aug 26, 2014 at 18:04
  • 2
    Using tape as a middle marker has contributed to death of a climber: publications.americanalpineclub.org/articles/13201212448/…
    – endolith
    Commented Jul 2, 2018 at 14:26
  • I would not be using dental floss but sewing yarn to mark the middle of the rope with a bit of yarn, and with a colour that stands out on the rope. Sewing yarn is available in many colours.
    – Willeke
    Commented Jul 2, 2018 at 18:36

I used fishermans thread, the sort used to bind the guide loops to the rod, as a whipping around the approriate point.

  • 1
    A whipping in the middle of the rope would fix the sheath and the core to each other, which is what you do not want.
    – Willeke
    Commented Jul 2, 2018 at 18:38
  • @Willeke The whipping does not truly 'fix' the sheath to the core, as they are still separate. I start the whipping using a darning needle so at to ensure that the thread stay with the outer, without damaging the outer (which can be an issue with a sharp needle). Under the designed extreme tension the core will narrow and slide internally as required. The example of a tape marker failure is worth noting. I also coil each half separately making the 'half rope' more obvious. The main concern is that the mid point itself becomes overused and worn, relatively speaking. Always check! Commented Jul 3, 2018 at 10:14
  • 2
    Maybe your whipping allows movements, a well made whipping by someone used to make whippings for use on boats will not allow any movement of the different layers. If you want to keep this answer, at least post a warning in it that it has to be a special 'non binding' whipping.
    – Willeke
    Commented Jul 3, 2018 at 15:35

The German Alpine Club (DAV) tested several permanent marker pen inks (Edding 3000, Retract 11 and Staedtler Lumocolor) and found no reduction in rope strength in static tests. So I would feel pretty safe in using one of them, despite the fact that they are not specifically sold as "rope markers".

Roughly translated from German:

It makes sense to mark the middle of the ropes. Many rappelling and lowering accidents might habe been prevented by this. Marking the middle with tape makes little sense as the tape is not very durable and might slip. Additionaly, it might get stuck on the prussik when rappelling.

Using the inks Edding 3000, Retract 11 and Staedtler Lumocolor, no relevant reduction in strength could be found in static testing. They can be regarded as adequate to mark the middle of ropes.

Another longer Explanation for those who speak german.

The Edding company even promised the DAV that the name of the pen would change if the composition changed, so that the 3000 pen should be safe for the forseeable future.


BlueWater Ropes says:

Marking pens are fine to use on ropes as long as they are water based laundry markers. Years ago solvent based markers were the norm. Some of the solvents used in these old pens could reduce the strength of the sheath strands marked. These days most pens are water based so this is not as much of an issue as in years passed. We recommend a Sharpie “rub a dub” laundry marking pen.

UIAA says:

Tests done by the UIAA Safety Commission and some rope manufacturers have shown that marking ropes with liquids such as those provided by felt-tipped pens can damage them; even with those markers, sold specifically for marking ropes. The test results have shown a decrease of up to 50% of the rope strength, more correctly: of the energy absorption capacity of the rope (expressed by the number of falls in the standard test method in accordance with the UIAA Standard101).

Therefore the UIAA Safety Commission warns against marking a rope with any substance that has not been specifically approved by the rope manufacturer of that rope.

Black Diamond thinks it's not likely to cause any harm, though they didn't make ropes at the time:

so I had my crack crew of engineers grab a few cords, mark them up with a Sharpie, and pull them in the tensile tester. As expected, the ropes always broke at the knot—the Sharpie's middle mark seemingly having no effect on the strength of the cord during this test.


I don't think Sharpies or any other permanent markers have really been proven to actually damage nylon—short-term or long-term. However, I can't recommend them for use on rope either because the manufacturers will not and cannot guarantee that the marker will always be free of possibly harmful chemical ingredients. In other words, they can change the formula on a whim and none of us would be the wiser.


I use a figure-eight loop. Fairly easy to remove when you need to. Also gives the possibility to descend on one or two ends of the rope if the middle is brought to your anchor.

Edit1: Of course not to permanently damage your core, it is advised to regularly (eg after each trip) take out the knot. This way the core gets a chance to recover.

Edit2: I strongly advise against marking the middle of your rope with a permanent marker. This for the simple reason that when you have to cut your rope, the "middle"-marking will still be there. When you have multiple middle-markings it will be hard to know which one really marks the middle when you need it.

  • "When you have multiple middle-markings it will be hard to know which one really marks the middle when you need it." Cut both ends by the same amount
    – endolith
    Commented Jul 2, 2018 at 14:38

Markers are never a good way to 'mark' your rope. Buy a rope that's already marked with another color. It's in any case better to do it old fashioned and find it using some rope techniques.

We use electrical tape on all our equipment. But I cannot guarantee its safety.

  • Please, if you vote down, comment why you think it's not a good answer :-)
    – sridesmet
    Commented Aug 6, 2015 at 8:33
  • 6
    Rope Markers are THE way to mark a rope. Its a trusted method, and globally used. Electrical Tapes? No way!!!
    – WedaPashi
    Commented Aug 9, 2015 at 8:12
  • I still recommend to buy a rope that is already marked by the manufacturer :-) I use electrical tape on my climbing gear. It comes loose after some time though. I know of some tests were the strength of the rope decreases with rope markers that are not produced by the rope manufacter. Yet, the strength is still bigger than a figure 8. So I guess you could state it's safe if you use the right rope marker.
    – sridesmet
    Commented Aug 10, 2015 at 10:09
  • 4
    -1. Show me one equipment manufacturer that expects electrical tape to be ran through their equipment. It sounds like a real risk of causing interference with a belay device or rope clamp--not to mention the adhesive will be working its way into the core, introducing the same risk of unknown chemicals that you're trying to avoid. I really wish I could give this an extra downvote or ten.
    – STW
    Commented Jun 29, 2016 at 0:21

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