How to Mark Your Fly Line, Lefty Kreh's Method

Listen to this Episode

This episode is brought to you by Star brite — Premium marine cleaning and maintenance for your boat.

Episode Show Notes

Marking your fly line means using a Sharpie to put a simple code of wide and narrow bands on the line, where a wide mark equals five and a narrow mark equals one, so you can read the line weight at a glance. It is an old-school trick straight from Lefty Kreh, and if you own a stack of fly rods and reels it solves the constant problem of not being able to tell an eight weight from a nine. In this How 2 Tuesday I show you exactly how to do it.

Watch and listen now: press play in the player above and follow along.

Frequently Asked Questions

How do you mark a fly line to identify its weight?

You use a Sharpie and a simple band system that Lefty Kreh taught: a wide bar equals five and a narrow bar equals one, and you add them up to get the line weight. Rotate the line in your hand as you mark so you coat both sides. For an eleven weight, you make two wide bars, five plus five for ten, then one narrow mark for the extra one. For a five weight, you just make a single wide bar. Read the marks, add the values, and you instantly know what the line is.

Why should you mark your fly lines?

Because if you own a bunch of fly rods and reels, it is very hard to tell one line from another, especially an eight from a nine or a nine from a ten. Some lines come printed with the weight, which is great if it stays on, but plenty of older lines have no markings, or the printing wears off. When you have a big trip coming up and want to put a fresh line on one rod, you need to know which of your other lines is which so you can keep a good one as a practice or spare line in your tackle bag.

What does Lefty Kreh's fly line marking system mean?

It is a simple value code: a wide Sharpie mark counts as five and a narrow mark counts as one. You combine wide and narrow marks to signify the line weight. So five and five makes a ten weight, and five, five, and one makes an eleven weight. It is old school and it works, which is exactly why Lefty used it. Once you learn the wide-equals-five, narrow-equals-one shorthand, you can read any line you have marked at a glance.

How long should you make the marks on your fly line?

About an inch and a half long. I choose that length on purpose, because once you get out in the sun with saltwater on the line, a shorter mark can fade and disappear, and then you are back to guessing. Make the bars a solid inch and a half, rotate the line as you color so you cover both sides completely, and the marks will survive a season of sun and salt so you can still read the line weight later.

Should you mark both ends of the fly line?

Yes. I put the marks on both ends of the fly line so no matter which end is showing, I can identify the line. Lines get loaded and reloaded, and you will not always have the same end out, so marking both ends means you can always read the weight without having to strip the whole line off to find the marked end.

Are the manufacturer stickers good enough for identifying lines?

They are fine if they stay put, but they usually fall off or get messed up over time. The little stickers that come with a fly line can go on your reels, which is handy, but they rarely last. That is why the best approach is the old-school Sharpie band method Lefty Kreh used, marked right onto the line itself, so the identification is permanent and travels with the line no matter which reel it ends up on.

How to Mark Your Fly Line

Here are the steps I walk through. This one is quick and easy to follow along with above.

  1. Grab a Sharpie. Hold a Sharpie in one hand and the fly line in the other, ready to rotate the line as you mark so you coat both sides.
  2. Know the code. Remember that a wide mark equals five and a narrow mark equals one, and you add the values to get the line weight.
  3. Mark the wide bars. For the fives, make wide bars about an inch and a half long, rotating the line to coat it all the way around, so a ten weight gets two wide bars.
  4. Add the narrow marks. For each one over a multiple of five, add a narrow mark, so an eleven weight gets two wide bars plus one narrow mark.
  5. Mark both ends. Repeat the same marks on the other end of the fly line so you can identify the line no matter which end is showing.

I unpack each of these in the episode. Press play in the player above.

Why You Need to Mark Your Lines

If you have eight, nine, ten, eleven, and twelve weights around, it is genuinely hard to tell a nine from a ten. Some lines come printed with the weight, which is great if it stays on, but plenty do not, or the printing wears off. When a big trip is coming and you want a fresh line on one rod, you need to know which of your other lines is which. I explain the problem in the episode, so press play in the player above.

The Lefty Kreh Band Code

The whole system is just wide equals five, narrow equals one, added together. Five and five is a ten, and a smaller mark after that makes it an eleven. I make my marks about an inch and a half long on purpose, because sun and saltwater will shrink a short mark until it disappears. I walk through the exact marking in the episode, so press play in the player above.

Mark Both Ends and Be Done

I mark both ends of every line so I can read it no matter which end is showing, and I do it the moment I get a new line. The manufacturer stickers are fine on your reels, but they fall off, so the Sharpie bands are the permanent fix. I cover the habit in the episode, so press play in the player above.

Final Thoughts From Me

Get in the habit of marking your lines the day you get them, wide for five and narrow for one, on both ends, and you will always know exactly what you are holding.

That is how to mark a fly line, the old-school Lefty Kreh way. Press play in the player above and we will talk next week.

More How 2 Tuesday Tutorials

How 2 Tuesday is my weekly series where I break down one fishing skill at a time, from knots and casting to gear, tactics, and the habits that make you a better angler. Watch and listen to every How 2 Tuesday episode from Tom Rowland.

People & Topics Mentioned

Lefty Kreh · marking fly line · fly line weight · Sharpie · fly line maintenance · whipped loop · How 2 Tuesday · Saltwater Experience

About Me

I'm Tom Rowland, a professional fishing guide based in the Florida Keys, host of the Tom Rowland Podcast, and the longtime host of the Saltwater Experience television show. On the podcast's How 2 Tuesday series I break down one practical skill or lesson at a time, from fishing technique and gear to the habits that make you a better angler, in short, focused episodes you can put to use right away.

Star brite
Premium marine cleaning and maintenance for your boat.
Shop Star brite
Free Knot Guide
Tom's free fishing knot guide for inshore and offshore.
Download Knot Guide
GORUCK
Getting ready for Murph? Get 20% off Weight Vests with code VEST20.
Shop The Weight Vest
MTN OPS
Nutrition for outdoor athletes. Use code TOMFREESHIP for free shipping.
Shop MTN OPS
1st Phorm
Premium supplements to fuel your body. Free shipping on every order.
Shop 1st Phorm
Nuvio Recovery
Red light therapy recovery mat. Use code TOM50 for $50 off.
Shop Nuvio Recovery

Subscribe to the Tom Rowland Podcast

Listen on Apple Podcasts Listen on Spotify

Never Miss an Episode

Subscribe to get the latest episodes, show notes, and exclusive content delivered straight to your inbox.

{"@context": "https://schema.org", "@graph": [{"@type": "VideoObject", "name": "How to Mark Your Fly Line, Lefty Kreh's Method", "description": "Tom Rowland shows Lefty Kreh's old-school method for marking a fly line with a Sharpie so you can read the line weight at a glance.", "thumbnailUrl": "https://i.ytimg.com/vi/6HuE_5hXYQU/maxresdefault.jpg", "uploadDate": "2022-01-25T09:00:00Z", "embedUrl": "https://www.youtube.com/embed/6HuE_5hXYQU", "contentUrl": "https://www.youtube.com/watch?v=6HuE_5hXYQU", "publisher": {"@type": "Organization", "name": "Tom Rowland Podcast"}}, {"@type": "PodcastEpisode", "name": "How to Mark Your Fly Line, Lefty Kreh's Method", "episodeNumber": 563, "datePublished": "2022-01-25", "description": "Right after whipping a loop, I show you an old-school Lefty Kreh trick: how to mark your fly line with a Sharpie so you always know which line is which. A How 2 Tuesday tutorial.", "url": "https://www.tomrowlandpodcast.com/episodes/tom-rowland-podcast-marking-your-fly-line-lefty-kreh", "author": {"@type": "Person", "name": "Tom Rowland"}, "partOfSeries": {"@type": "PodcastSeries", "name": "Tom Rowland Podcast", "url": "https://www.tomrowlandpodcast.com/"}}, {"@type": "Article", "headline": "How to Mark Your Fly Line, Lefty Kreh's Method", "description": "Tom Rowland shows Lefty Kreh's old-school Sharpie method for marking a fly line so you always know which line is which. A How 2 Tuesday tutorial.", "datePublished": "2022-01-25", "dateModified": "2026-06-03", "author": {"@type": "Person", "name": "Tom Rowland", "url": "https://www.tomrowlandpodcast.com/about"}, "publisher": {"@type": "Organization", "name": "Tom Rowland Podcast", "logo": {"@type": "ImageObject", "url": "https://www.tomrowlandpodcast.com/favicon.ico"}}, "mainEntityOfPage": "https://www.tomrowlandpodcast.com/episodes/tom-rowland-podcast-marking-your-fly-line-lefty-kreh", "image": "https://i.ytimg.com/vi/6HuE_5hXYQU/maxresdefault.jpg"}, {"@type": "HowTo", "name": "How to Mark Your Fly Line", "description": "Use Lefty Kreh's wide-equals-five, narrow-equals-one Sharpie code.", "step": [{"@type": "HowToStep", "name": "Grab a Sharpie", "text": "Hold a Sharpie in one hand and the fly line in the other, ready to rotate the line as you mark so you coat both sides."}, {"@type": "HowToStep", "name": "Know the code", "text": "Remember that a wide mark equals five and a narrow mark equals one, and you add the values to get the line weight."}, {"@type": "HowToStep", "name": "Mark the wide bars", "text": "For the fives, make wide bars about an inch and a half long, rotating the line to coat it all the way around, so a ten weight gets two wide bars."}, {"@type": "HowToStep", "name": "Add the narrow marks", "text": "For each one over a multiple of five, add a narrow mark, so an eleven weight gets two wide bars plus one narrow mark."}, {"@type": "HowToStep", "name": "Mark both ends", "text": "Repeat the same marks on the other end of the fly line so you can identify the line no matter which end is showing."}]}, {"@type": "FAQPage", "mainEntity": [{"@type": "Question", "name": "How do you mark a fly line to identify its weight?", "acceptedAnswer": {"@type": "Answer", "text": "You use a Sharpie and a simple band system that Lefty Kreh taught: a wide bar equals five and a narrow bar equals one, and you add them up to get the line weight. Rotate the line in your hand as you mark so you coat both sides. For an eleven weight, you make two wide bars, five plus five for ten, then one narrow mark for the extra one. For a five weight, you just make a single wide bar. Read the marks, add the values, and you instantly know what the line is."}}, {"@type": "Question", "name": "Why should you mark your fly lines?", "acceptedAnswer": {"@type": "Answer", "text": "Because if you own a bunch of fly rods and reels, it is very hard to tell one line from another, especially an eight from a nine or a nine from a ten. Some lines come printed with the weight, which is great if it stays on, but plenty of older lines have no markings, or the printing wears off. When you have a big trip coming up and want to put a fresh line on one rod, you need to know which of your other lines is which so you can keep a good one as a practice or spare line in your tackle bag."}}, {"@type": "Question", "name": "What does Lefty Kreh's fly line marking system mean?", "acceptedAnswer": {"@type": "Answer", "text": "It is a simple value code: a wide Sharpie mark counts as five and a narrow mark counts as one. You combine wide and narrow marks to signify the line weight. So five and five makes a ten weight, and five, five, and one makes an eleven weight. It is old school and it works, which is exactly why Lefty used it. Once you learn the wide-equals-five, narrow-equals-one shorthand, you can read any line you have marked at a glance."}}, {"@type": "Question", "name": "How long should you make the marks on your fly line?", "acceptedAnswer": {"@type": "Answer", "text": "About an inch and a half long. I choose that length on purpose, because once you get out in the sun with saltwater on the line, a shorter mark can fade and disappear, and then you are back to guessing. Make the bars a solid inch and a half, rotate the line as you color so you cover both sides completely, and the marks will survive a season of sun and salt so you can still read the line weight later."}}, {"@type": "Question", "name": "Should you mark both ends of the fly line?", "acceptedAnswer": {"@type": "Answer", "text": "Yes. I put the marks on both ends of the fly line so no matter which end is showing, I can identify the line. Lines get loaded and reloaded, and you will not always have the same end out, so marking both ends means you can always read the weight without having to strip the whole line off to find the marked end."}}, {"@type": "Question", "name": "Are the manufacturer stickers good enough for identifying lines?", "acceptedAnswer": {"@type": "Answer", "text": "They are fine if they stay put, but they usually fall off or get messed up over time. The little stickers that come with a fly line can go on your reels, which is handy, but they rarely last. That is why the best approach is the old-school Sharpie band method Lefty Kreh used, marked right onto the line itself, so the identification is permanent and travels with the line no matter which reel it ends up on."}}]}]}