Marking Ropes

Mark Chisholm

This post comes to us through the efforts of Tom Dunlap. I am just going to post it here for him, so here it is:

The use of ink markers to mark the middle of rock climbing ropes has been controversial. The UIAA and some of the rope manufacturers have started to do some break testing and have released some statements about the findings. Even though arborists use their ropes differently than rock climbers, we should at least be aware of what is happening in other areas of the vertical world.

Strong limbs and snug ropes,


A recent thread on rec.climbing covered this issue. I’ve taken the time to cull through and edit some of the more relevant posts from the thread. To read the whole thread, follow this link:

Otherwise, the following will give you an idea of the gist of the discussion.

From: Dawn Alguard (

I got this in the mail from Sterling Ropes today:

"Rope Marking 101

"This has been and continues to be hot topic among climbers. The following is preliminary recommendations that were developed from the recent 2001 UIAA Safety Commission, and brief overview of the results of recent and earlier tests conducted by the German Alpine Club.

"Recent tests conducted by two rope manufacturers have found significant strength reductions (45% reduction after seven days influence, and more than 50% reduction after three weeks influence) after application of markers on the rope. In the German study, when the marked portion of the rope was placed on the edge of the orifice and tested, the ropes held significantly fewer falls. These tests were done a few years ago when various other
substances were also tested. Urine causes a 30% reduction in number of drops held. Insect repellent apparently does no harm. Acids, we know, are deadly in the true sense of the word. Clearly there is only a problem if the rope happens to be loaded over an edge precisely at the marked section. It is believed that falls at other places in the rope will not be significantly affected. Tests were done in 1997/98.

"It has also been found in previous research and testing that the marker companies change the ingredients in the markers based on availability and price of the chemicals. Based upon these facts and knowing that there is no consistent formula, it is not recommended using marks of unknown ingredients for use on ropes and webbing.

"Test Protocol - The marked location was placed directly over the 'edge', i.e. in the plane of the orifice in the UIAA drop test apparatus. This is the location where all ropes break in the test. The number of falls was reduced from 10 to 12 falls down to 6 to 8 falls. Note that the rope is still perfectly safe as long as the marked location does not lie on an edge during a fall. This is an unlikely situation, but we still do not like the odds. The UIAA meeting notes from 1998 state that marking a dynamic rope with a marker, even one that is marketed as a rope marker, effectively cuts the breaking strength in half when the rope falls over an edge at the area marked. NOTE: these problems will not arise with middle or other markings
applied by the manufacturer, such as Sterling's whipped center marker.

"These findings will be made in an announcement drafted by the President of the UIAA in a warning statement about the use of any marker on plyamid (perlon, nylon) based upon the above tests."


This is a link to the UIAA page and the text from the announcement

Notification Concerning the Marking of Ropes

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.

It is not possible for the UIAA Safety Commission to test all markers that are commercially
available and can be used for marking ropes. Furthermore it would be impossible for the UIAA Safety Commission to keep such information up-to-date. In addition, the effect of any rope marker seems to vary with the make of rope. Hence, all the UIAA Safety Commission can do is to warn mountaineers and climbers.

Following are a few of the more relevant follow-up posts from rec.climbing

Issued: April 2002

Richard Goldstone (
Subject: Re: Middle marks: it's official

Like most of the other posters, I find it hard to get too worked up about this, and I do think there reasons for having a middle mark. One applies to multiple raps with a single rope. As you pull the rope, it is efficient (and so, in pressure situations, valuable) to be able to feed the pulled end through the next anchor. If you do this, you never have the two ends to coil together as a way of locating the middle, and a middle mark allows you to set up the next rap properly.

I also wish, with others, that the testing methods and protocols were made public. I keep wondering whether the testing of marked ropes is different from the testing of unmarked ropes. After every test drop, the rope stretches. Although allowed to "rest," it does not recover completely and so is slightly longer after each test. I have no idea how much elongation happens, but it seems that because of the stretching, an unmarked rope will have a slightly different part over the bar at each drop. On the other hand, I imagine that a marked rope would be adjusted each time to reposition the mark on the bar. If these wild speculations are true, then the tests are not equivalent and the chemical effects of marking may be confounded with the marked test's concentration on one particular spot. (The fact that different results are obtained from different treatment periods indicates that there may be effects associated with the marking substance itself.) Finally, I find the language of "strength reductions" to be a bit hysterical. What has been reduced is the rope's ability to recover its elasticity over and over again, and that ability has not been reduced below UIAA standards. Very few ropes are involved in fall-factor two catches in real life. I'm going to go out on a limb and claim, with absolutely no statistics of any kind to back this up, that no rope has ever had to endure two fall-factor two catches in real life, because the tiny fraction that had one such catch were retired with honors after the incident. These apparent reductions in number of "recovery cycles" are interesting and worth understanding, but in a dangerous world, they ain't high on my list of worries.

Chiloe (

Are "strength reduction" and "reduction in number of falls held over an edge" interchangeable terms? To me they sound different. A true 50% strength reduction suggests the marker had turned the rope's sheath to tissue paper, and/or soaked through to damage the core. But that isn't what the tests found.

If marker damage really only affects breaking over an edge (and _not_ straight pull strength), that implies that marking affects the dynamic properties -- ability to stretch or to spread out and distribute the load over the edge. Do these effects matter for situations other than the unlikely mid-rope-edge-loading scenario? The report (at least, as summarized here) gives no analysis, and raises more questions than it answers.
From: Dawn Alguard (
Well, the report as summarized here is nothing new. We went through all this a couple of months ago. I was just pointing out that it has now been "officially" said. The same arguments we made when last this arose still apply, i.e. one fall ain't gonna kill you and it's not so easy to get the middle mark over an edge without taking one whopper of a fall anyway. Now if you choose to repeatedly take the type of fall that would load the middle mark over an edge, I guess you're going to be SOL somewhere around the 6th one.

I personally would still climb on a rope with a marker-marked middle, however I've never been in the habit of marking mine that way so I don't know whether or not this news would change my practices if I were. Here's the best URL for the previous discussion:


This post puts the whole discussion in perspective.

From: Michael Boos (
Asked about the subject, Pit Schubert , who has developed most of the UIAA norms during the past 25 years and knows about testing of ropes (and other stuff) probably more than anybody else. He is also an excellent climber himself still, although retired from his job with the DAV one year ago has replied to me as follows:
das ist alles kein wesentliches Problem, denn desbalb kann ein Seil nicht reissen, nur dann, wenn gerade die zwei oder drei Zentimeter Markierung bei einem Sturz auf einer Felskante zu liegen kämen, dann würde das Seil schon bei einer weniger scharfen Kante oder bei einer etwas geringeren Fallenergie reissen. Zur Information, wie häufig eine Scharfkantenbelastung in der Praxis vorkommt: In den letzten 19 (!) Jahren hat es unter deutschen und österreichischen Kletterern gerademal einen einzigen Scharfkanten-Seilriss gegeben, und das bei sicher Hunterttausenden von Sportkletterstürzen jedes Jahr. - Also alles in allem: es besteht keine wesentliche Gefahr.

Freely translated it means:
these findings do not constitute a serious problem, because a rope may not break because of that except for the case where exactly these two or three cm of marked rope are located exactly over an edge in case of a fall, where in that very case this edge need not be that sharp or the fall that heavy to break the rope. How much does such a fall happen with the rope loaded over a sharp edge: During the past 19 years German and Austrian climbers
have had just one such rope break over a sharp edge. So: no real danger.


In the UK (and soon Europe under the temporary work at height directive) All climbing equipment carrying a person i.e ropes, harnesses, karabiners and lanyards have to be individually marked and recorded (LOLER regs - lifting operations and lifting equipment regulations '98).

The best way of marking ropes that we have found, is to wrap surgical tape around one rope end. This is then written on with a simple ID no. and covered with transparant shrink wrap. This has stood up well to the UK wet weather, but does require replacing after a period of time as it becomes difficult to read, or just pulls off. This is no big deal, as it is so easy to replace, even in the field.


Active Member
I want to mark my ropes at 10' intervals. The reason is so I can have a better perspective of distances.

Example: A climber is in a tree. The climbers rope is marked at 10' intervals. There are a few marks on the climbers' rope which is hanging below the climber. How high is the climber? On inspection of the marks on the rope and knowing there is 10' between each mark, the climber is roughly the distances of the marks + whatever extra rope is seen outside of the apparent marked distances.

This is helpful information that hasn't been directly available to climbers. It's helpful for rigging applications and anything else 1 needs when knowning distances is important.

The above post and discussion is for dynamic rope which is made of nylon. Arborist ropes are made primarily out of polyester. There's no discussion or data about using water or alcohol based markers on polyester ropes.