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MYOG: 3mil Plastic Tarps

Practice makes perfect: using polyethylene to prototype designs means I can spend less and try more variations before sewing a final product in technical materials.

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by Jerry Adams | 2011-02-08 00:00:00-07


MYOG: 3mm Plastic Tarps - 1
I have made several versions similar to this. In my three nights under this, it rained really hard with strong wind one night. The only problem I encountered was that I put my sleeping bag in an area that became a puddle about half an inch deep. Fortunately, my air mattress is 1.0 inch thick so I stayed above the water.

I may get beat up for talking about using plastic for a backpacking tarp on Backpacking Light, because it’s so cheap and flimsy, but here goes!

I have spent many nights sleeping under polyethylene tarps. They’re cheap, fairly lightweight, as waterproof as any other material, and possible to make robust enough to survive fairly bad weather. I’ve done about eight different designs and usually just use them on one trip of up to four nights.

I mainly use polyethylene tarps to prototype a design I want to verify before doing it in more expensive material. Such tarps would also be good for backpacking on the cheap, as you'd be able to equip four people for about $20 and some labor. In these economic times, frugal is popular.


I have always used 3 mil (0.003 inch thick) polyethylene, which is commonly used for protecting stuff while you’re painting. You can get a 10 x 25 ft piece from Home Depot for $10, which is enough for two or more tarps, depending on the tarps' size. The 3 mil weighs 2.0 oz/yd2, which is fairly light.

Just to experiment, I made a tarp out of 2 mil polyethylene, which weighs 1.4 oz/yd2. It held up in my backyard, through rain and wind, for more than a week before the duct tape reinforcing came off, which wasn’t even a polyethylene failure. Based on this test, I may use this lower weight sheeting instead.

As a comparison, silnylon, a common lightweight tarp material, is about 1.4 oz/yd2 and Cuben, the state of the art material, is 0.75 oz/yd2 for the thickness most commonly used for tarps.

MYOG: 3mm Plastic Tarps - 2
For guylines, I use Mason’s twine. (Shown: Mason’s twine, some of the slippery pale stuff that doesn’t work very well, and 16-oz coffee cup for scale.) I use this for all my tarps, food hanging line, ditty bag ties, etc. It’s fluorescent red to minimize running into or losing it. Home Depot sells it for $5 for 250 yards, which is enough for 30 tarps. The braided version works best for using a taut line hitch. It’s #18 thickness (0.0625 inch diameter). It weighs about an ounce for 25 feet, which is enough for most tarps.

Several other common guyline materials and weight for 25 feet:

  • Triptease: 0.7 ounce
  • Aircore 2: 0.25 ounce
  • Aircore 1: 0.1 ounce

I tried some similar line from Lowes, and it was thinner and slipperier so it didn’t work very well. The Home Depot line was a brighter fluorescent color. This could just be a particular lot and a different store, or a completely different product. I’ve also used twisted twine, but it comes untwisted too easily.

I use #0 size grommets on my tarps (0.25-inch diameter hole). Outdoor Wilderness Fabrics sells a grommet setter, hole punch, and 24 grommets for $15. I have a grommet setter similar to the OWF version, though mine is cast iron. You have to hammer on the die to squish the grommet down, and it’s a bit of a trick to get it right. You have to hammer the grommet enough so that it doesn’t rotate around in the plastic, but if you hammer it too much, the grommet's edges will cut the plastic. You should experiment first - hammer it too much so it cuts the edge to see what to avoid. I sometimes have to pry the grommet from the die with a screw driver.

I use readily available duct tape for reinforcement for guyline tieouts. One roll is enough for many tarps, and you probably don't even need to go buy some because you've got it lying around.

I have used two trees to hang a tarp, but it’s hard to find a location with a flat area between two trees. I like camping in alpine areas without many trees anyway, so I finally got a pole which works much better for a one-pole tarp configuration. It’s easier to find one tree next to a flat area. I don’t normally use trekking poles but those make excellent tent poles.

I use some Easton Aluminum tent poles from TentPole Technologies. Quest Outfitters is another good source. I get the 26-inch lengths and cut them down to about 21 inches for each section - 41-inch length as assembled. This is pretty flimsy and could collapse in strong winds, or could collapse if you run into it, but is quite lightweight - 1.5 ounces for the two-section pole. I’ve used this in 20 MPH winds a number of times and have gotten away with it. The tip fits into the #0 grommets. I whittled down the tip a little because it’s a tight fit.

Guyline and Pole Reinforcement

The first method I’ve used to attach guylines is to put a small pebble inside the corner of the plastic and tie around it with the guyline. If you’re not familiar with this, it can be handy in repairing a tarp that rips out in the field. I object to carrying pebbles, so I use 0.75-inch diameter styrofoam balls from the craft store.

MYOG: 3mm Plastic Tarps - 3
First put the ball in the corner and wrap around it with guyline.

MYOG: 3mm Plastic Tarps - 4
Tighten and tie a knot.

This is a strong connection and distributes the load to the plastic evenly. The only bad thing about this method is that it doesn’t pull on the precise corner of the tarp, but at a point a couple inches in from the corner, so there will be a few inches loose all around the tarp. Because it's not tensioned, it will flap in the wind. Also, this method doesn’t work very well as a connection to the sides of the tarp, only in the corners.

MYOG: 3mm Plastic Tarps - 5
Loose edges.

MYOG: 3mm Plastic Tarps - 6
The method I have used most often is duct tape for reinforcement with a grommet to run the guyline or pole tip through.

For example, last June I used a tarp in windy, rainy conditions for three nights at Burnt Lake and East Zigzag Mountain on Mount Hood in north central Oregon. Winds got up to about 20 MPH, and while the tarp held up fine, I noticed the duct tape slipped about 1/8 inch relative to the plastic. The adhesive on duct tape isn’t that great, and this wouldn’t last many more nights. Any suggestions on a better tape to use?

I wanted to find a way to attach guylines that would last a little longer than duct tape, so I constructed a simple test - 3 mil plastic, duct tape, and grommet on one side, guyline around foam ball on the other side. I then used it to hold 8 pounds (gallon milk jug of water).

MYOG: 3mm Plastic Tarps - 7
Test setup.

After about six hours, the duct tape slipped a little (which is what happened after three nights of backpacking in wet windy weather), and after twelve hours, the duct tape slipped off completely. This was my control... then I used the test setup to evaluate a few other methods.

First I put five staples through the duct tape/plastic. It held up fine for a week, so I think this would work well for a tarp on multiple trips.

Second, I tried something not requiring a grommet.

MYOG: 3mm Plastic Tarps - 8
First put the duct tape on one side of plastic and place knotted twine on the very edge of the plastic.

MYOG: 3mm Plastic Tarps - 9
Fold the duct tape over onto the other side of plastic, enclosing the knotted twine.

This held up for about a week in my test setup - the twine eventually slipped out of the duct tape. I also used it on a 2 mil plastic tarp that held up in rain and wind for a week before the duct tape slipped off, so this would make a reasonable connection for one trip. I might make the loose end longer and tie it to the main line with a taut line hitch so it won’t slip out.

I also used the test setup with 2 mil plastic. Foam ball worked best, staples in duct tape worked pretty well, no staple slipped off after about a day, knotted line without grommet held up for three days.

MYOG: 3mm Plastic Tarps - 10
I use a taut line hitch to tighten guylines. I don’t want to insult anyone by assuming they don’t know this knot, but just in case, here’s a taut line hitch loose.

MYOG: 3mm Plastic Tarps - 11
Taut line hitch tightened up. You have to really pull on the two loose ends (marked with red arrows) to tighten it up enough to hold on thin twine like this. After the tarp is set up and the lines are under tension, go over the taut line hitches one more time, really tightening them up. Also push the loops together on the two tight ends (not marked with arrows) to get the knot so it won’t slip.

This thin line is marginally thick enough to use a taut line hitch. You can always use tensioners instead of taut line hitch. For example, BPL's Aircore Nano Dyneema Spectra Guyline weighs 0.8 ounces for 50 feet of cord plus 12 tensioners, all for $15.99.

I use 0.34-inch Easton Aluminum poles, and the tips fit in a #0 (0.25-inch) grommet. This pole is a little light and might collapse, especially if you accidentally run your foot into it, but I’ve used it for years, with a 40-inch length, and it has never collapsed on me.

MYOG: 3mm Plastic Tarps - 12
If you don’t want to use a grommet to hold the pole, then use a guyline and make a clove hitch around the tip of the pole. This would work with a bigger pole, trekking pole, or stick.

Design Examples

Classic Pup Tent

MYOG: 3mm Plastic Tarps - 13
I used this style tent for my first backpack when I was 12 years old, and it is probably the most common tarp method. Basically, you just string a line between two trees or poles, put the tarp over it, and guy down the four corners

It works better if you have a guyline tieout at the middle of the tarp on each side at the ridgeline. Have a short guyline and tie it to the ridgeline line with a taut line hitch. This keeps the tarp stretched out along the ridgeline. Alternately, you can omit the ridgeline line that goes under the tarp, and instead go from both sides of the tarp to tree or pole, but this puts more stress on the guyline tieout, and if it fails, the tarp will collapse on you (this isn't a problem with fabrics so much as it can be with plastic).

I don’t really care for this design because it requires two poles, which is heavier, and if the wind blows into either end, then rain will blow in and get you wet. You can try variations, like lowering one end to reduce rain blowing in or making the tarp longer or wider. Adding a catenary ridgeline curve is out of the scope of a plastic tarp, but improves performance dramatically.

One Pole Tarp

MYOG: 3mm Plastic Tarps - 14
One pole tarp, in plastic.

This is what I have used more than anything else. On one end it’s like a pup tent, and on the other end, the two corners are about 40 inches apart and guylined to the ground. I added a “beak” at the pup tent end to reduce rain blowing in - folded the plastic and used duct tape/grommet to pull out with guyline. There’s duct tape with a grommet at the peak to put the pole through.

This uses less fabric than a pup tent because it’s narrower on one end. Only one end is open, which can allow rain in, which is bad, but only half as bad as a pup tent's two ends. It has only one pole which weighs less than a two-pole pup tent configuration. It is also easy to find a spot where you can use a simple tree instead of a pole, making it possibly a no pole design.

I’ve used various versions of this on about six trips of three or four nights each over the last couple years. I stayed fairly dry, and it held up pretty well to the wind. Obviously, you want to point the foot end into the wind to minimize rain blowing in, but the wind can always shift on you and defeat this idea.

A good size for one person is 40 inches wide at one end, 76 inches wide at the other end, and 9 feet long. Five square yards of fabric weighs about 10 ounces in 3 mil or 7 ounces in 2 mil or silnylon. Pole and stakes are maybe 4 ounces, so this makes for a pretty lightweight package.

MYOG: 3mm Plastic Tarps - 15
After successful polyethylene versions, I made one with silnylon to be lighter and more durable. I lengthened the beak and put in a zipper. I made catenary curves from the pole peak to each of the two corners on the low end.

MYOG: 3mm Plastic Tarps - 16
Head end view with zipper open. This weighs 11 ounces, plus 2 ounces for the pole and 1.25 ounces for the stakes.

Minimalist Tarp

I wanted to have an even lighter tarp that provides a better view from my sleeping bag for when there is only a small chance of a little rain or dew. I’ve slept without a tarp many nights when there was dew, and I slept fine and stayed dry inside, but then in the morning I have to dry things off and any gear also has to be dried off.

My idea is to have a tarp 44 inches wide guyed to the ground and 76 inches wide with two poles on the other end, 6 feet long. This only covers the top half of my sleeping bag, but my bag is water resistant - good enough for dew or slight rain. If it’s continuous hard rain, I’ll get wet.

MYOG: 3mm Plastic Tarps - 17
In 3 mil polyethylene it weighs 7 ounces. The poles weigh 3 ounces. The stakes weigh 1 ounce. I used this on one trip, and I was okay with it. I really like how I can see out of it almost as well as no tarp at all, but it isn't wind resistant.

MYOG: 3mm Plastic Tarps - 18
I liked it enough to make a version with polyester spinnaker cloth from Seattle Fabrics. I lengthened it a little to 7.5 feet.

MYOG: 3mm Plastic Tarps - 19
I tried it one night. When the winds got more than 20 MPH it was really noisy so I just took it down. It would help to have catenary curves on the two ridges.

The fabric is advertised as 0.75 oz/yd2, but I weighed it as 1.1 oz/yd2. It weighs 7 ounces, plus 3 ounces for poles and 1 ounce for stakes. I’ll play with this on a few trips to see if I like it, and probably find some modification to keep me busy.


If you enjoy making your own gear but hate making mistakes on expensive performance fabrics, get familiar with polyethylene. You can try several variations before making your first cut on the pricey stuff, and it's even sturdy enough for field testing.


"MYOG: 3mil Plastic Tarps," by Jerry Adams. (ISSN 1537-0364)., 2011-02-08 00:00:00-07.


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MYOG: 3mm Plastic Tarps
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Addie Bedford
(addiebedford) - MLife

Locale: Montana
MYOG: 3mil Plastic Tarps on 02/08/2011 15:14:17 MST Print View

Companion forum thread to:

MYOG: 3mil Plastic Tarps

Edited by addiebedford on 02/08/2011 21:56:38 MST.

Jeff Hollis
(hyperslug) - MLife
Packing Tape on 02/08/2011 15:33:03 MST Print View

Great article Jerry.

I have had great success with clear packing tape, usually 3M brand. I always have some around for shipping but have used it on a few pieces of gear. I used it to join closed sell foam together to make a koozie or insulator for my water bottle which I also use as a cup. The foam pealed off before the tape ever gave way.I have marked ounces and quarts on water bottles and playpus with a sharpie and then covered the writing so it would not rub off.

I have not tried it with polyethylene but bet it would work well. Could also use it to attach 2 pieces together and I bet is much lighter than duct tape.

Keep up the experimentation and good work.

Edited by hyperslug on 02/08/2011 15:43:57 MST.

Ken T.
(kthompson) - MLife

Locale: All up in there
Re: MYOG: 3mm Plastic Tarps on 02/08/2011 15:35:19 MST Print View

Don't forget to recycle. Thanks Jerry.

Devin Montgomery
(dsmontgomery) - MLife

Locale: one snowball away from big trouble
Re: MYOG: 3mm Plastic Tarps on 02/08/2011 16:21:05 MST Print View

I think the title should read "MYOG: 3mil Plastic Tarps." 3mm would be heavy duty indeed. :)

+1 on using mason's line for guy lines. I started with this stuff because I just had some around, but it's pretty strong.


Locale: Pacific Northwet
Re: Re: MYOG: 3mm Plastic Tarps on 02/08/2011 17:14:31 MST Print View

Neat article. I've made similar tarps before. I agree the 3 mil is the perfect thickness, 2mm is a bit to fragile, 4mm too heavy. 3mm is a good balance.

You don't really need grommets for the corners, a sheetbend attachment is super secure and does not weaken the tarp corners or add weight. You can even eliminate the ridgeline grommets if you just run a line between two trees, though it's harder to get a tight pitch that way.

Edited by DanG on 02/08/2011 17:15:21 MST.

Eugene Hollingsworth
(GeneH_BPL) - F
Poly vs Tyvek for this application? on 02/08/2011 17:41:10 MST Print View

Just knowing someone would actually use poly for a tarp adds credibility to the idea. Nice!

A quick question: how, in your opinion, is using poly different than Tyvek? Both are light, and cheap.

Tad Englund
(bestbuilder) - F - MLife

Locale: Pacific Northwest
MYOG: 3mm Plastic Tarps on 02/08/2011 17:56:30 MST Print View

Jerry, is good to see people are still thinking about how to do things inexpensively. One other option that would work for your guy lines instead of tape, pebbles, balls or grommets is to just tie a sheet bend knot with the plastic and line (a double sheet bend works even better). You get the total strength of the plastic and line and it can be placed right in the corner for a good tight pitch.

I started my scouts out with a piece of plastic and mason line and we use them for the whole summer. The boys re-used the plastic for ground cloths the next few years when the troop bought "real" tarps. I think some of them still are using the ground cloths. All in all the cost was minimal.

Jeff Hollis
(hyperslug) - MLife
Trail Trash on 02/08/2011 18:30:45 MST Print View

A Polyethylene tarp, a backpack made from a ForceFlex trash bag, a stove from a Budweiser can, and a sleeping bag from bubble wrap. And people will call you "trail trash"! :)

Eugene Hollingsworth
(GeneH_BPL) - F
RE: Trail Trash on 02/08/2011 18:51:27 MST Print View

I just lost a few brain cells on that one.... ugh. LOL.

Edited by GeneH_BPL on 02/08/2011 18:52:22 MST.

John Donewar
(Newton) - MLife

Locale: Southeastern Louisiana
Re: RE: Trail Trash on 02/08/2011 20:47:31 MST Print View


On the silnylon version of your tarp with the catenary curves, are there 3 seams on the top section of silnylon?

In the picture the material seems to "gather" in the center of the footend of the tarp. It makes me think that there is a third seam.

Silnylon Tarp

Party On,


Edited to add picture for clarification of my question.

Edited by Newton on 02/08/2011 20:53:21 MST.

Addie Bedford
(addiebedford) - MLife

Locale: Montana
mil vs mm on 02/08/2011 21:55:40 MST Print View

Thanks guys. This week is KILLING me! No more errors on my part, okay?

Okay. Now off to bed for me. Night all!

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Packing Tape on 02/09/2011 02:07:44 MST Print View

Hi Jerry

I haven't used PE sheet for an actual tent, but I have used rolls of it to make patterns for my tents.

Duct tape has a rubber adhesive, and this will creep. OK for quick repairs, but not for anything permanent.

Packaging tape comes in two varieties: cheap Chinese with a lousy adhesive which lets go, and expensive brand-name with a good adhesive. Brands like 3M, Husky, Nitto, Scotch should be fine. As it is a lot lighter than duct tape, try using a couple of layers.

However, really permanent-bonding anything to PE is hard to do without using really specialised adhesives which cost a LOT. Don't bother.


Erik Danielsen
(er1kksen) - F

Locale: The Western Door
RE: Tapes on 02/09/2011 09:35:33 MST Print View

Reinforced packing tape comes in a lot of varieties with different fibers, so I'd take a look around. I've used 1/2" wide no-name reinforced packing tape off the shelf of a convenient store as actual guylines to string up a sheet of plastic for a last-minute night outdoors, and they held up just fine. I imagine they'd be excellent reinforcements. Giving ridgelines a strip of tape and arranging it so that the tape (rather than the plastic) bears most of the load may provide even greater durability.

I know there is a heavy-duty transparent duct tape that is also useful for its UV resistance, but since it does have a rubber-based adhesive (similar to normal duct tape but more durable) it's probably less useful for projects involving poly (sticks great to mylar, though). Perhaps you can find a packing tape brand with extra UV resistance?

Dennis Park
(dpark) - MLife

Locale: San Francisco Bay Area
Re: RE: Tapes on 02/09/2011 09:55:01 MST Print View

Would Gorilla tape have a place here?

Andrew Sleigh
(AndrewSleigh) - F
Or using cheap nylon on 02/09/2011 10:19:53 MST Print View

Prototyping is definitely the way to go (at least until you're pretty competent at design and construction, and you have a pattern you're confident will work.

I prototyped the '5yds to UL' tarp using cheap nylon (£2/m vs £7-8/m for silnylon), documented here:

I learned a huge amount, and I'm very happy I didn't use expensive fabric for my first version.

(I'm also envious of the access you Americans seem to have to light, cheap, technical fabrics!)

Douglas Frick
(Otter) - MLife

Locale: Wyoming
Re: RE: Tapes on 02/09/2011 11:01:39 MST Print View

>Would Gorilla tape have a place here?

Gorilla tape hasn't slipped in my applications, but it is heavier than most duct tape. Good-quality packing tape sticks to plastic well, and is significantly lighter. I made pack straps from non-reinforced packing tape and stuck them onto a 40-pound bag of wood pellets, and they held fine (total weight of pellet-bag pack, after dumping the pellets: 2.1 oz; waterproof, too).

Also, the comments about using a sheet bend on the corners are right on: no need for tape or grommets, and tension is distributed through material better.

Edited by Otter on 02/09/2011 11:49:26 MST.

John Nausieda
(Meander) - MLife

Locale: PNW
re tape on 02/09/2011 11:25:35 MST Print View

I've used 3m packing tape inside my dishwasher to seal off a vent which was steaming into our kitchen cabinets and affecting their finish. It's been in there for ten years. If you smell the adhesive when you apply it it smells like vinegar. To say it is water resistant is an understatement

J Thomas Peterson
(tpeterson1959) - MLife

Locale: Southwest
Great Article on 02/09/2011 11:46:08 MST Print View

My very first camping experience was when I was only four years old, circa 1964. My dad took my mom, my little brother and me camping along the coast of the Olympic Peninsula. We slept under a plastic sheet every night. I remember waking up to rain on Agate Beach and being amazed that we were dry - that was definitely "the moment" for me!

I agree with Tad, too; it's great to see you using inexpensive, readily available materials. I often wonder how many people never even try getting out because they just can't bear the idea of spending up to several hundred dollars on the gear that's "recommended" in some of the popular magazines.

Again, great article!

Wesley Witt

Locale: Northwest
Re: MYOG: 3mil Plastic Tarps on 02/09/2011 13:20:21 MST Print View

Reminds of my childhood camping with the old school tube tents!

Jeff Hollis
(hyperslug) - MLife
Re: Re: MYOG: 3mil Plastic Tarps on 02/09/2011 13:28:09 MST Print View

In day glow orange not doubt!