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Reviews > Navigation and Map Gear > Accessories > Sea to Summit TPU Map Case > Test Report by Lori Pontious

Sea to Summit TPU Map Case
Test Series by Lori Pontious

INITIAL REPORT - January 2, 2012
FIELD REPORT - March 20, 2012
LONG TERM REPORT - May 28, 2012

Tester Information

NAME: Lori Pontious
EMAIL: lori.pontious (at)
AGE: 45
LOCATION: Fresno County, California, USA
HEIGHT: 5'7" (1.7 m)
WEIGHT: 165 lb (75 kg)

I backpacked, camped and fished all over the lower 48 states with my family as a kid, and then life happened. I restarted these activities about four years ago - I dayhike or backpack 2-6 times a month. I am between light and ultralight. I have a hammock system and own a Tarptent. My base weight depends upon season and where I go.

Product information

Manufacturer: Sea to Summit
Manufacturer URL:
Listed Weight: 2.7 oz (78 g)
Actual Weight: 2.5 oz (71 g)
Listed Size: Medium, 11.1 x 13.07 in (282 x 332 mm)
Actual Size (measured): 11.42 x 13.78 in (290 x 350 mm)
Available Sizes: Small, 8.3 x 11.9 in (212 x 302 mm) Medium, 11.1 x 13.07 in (282 x 332 mm) Large, 13.07 x 16.9 in (332 x 430 mm)

Product Description

The TPU Guide Map Case (aka the case, or the map case) is a Ziploc® sealed protective case designed to protect paper maps. The case is made of rectangular clear UV stabilized Thermoplastic Polyurethane, with strips of hook and loop that attach the ends of the case to each other. There are attachment loops at each corner large enough to be used with carabiners or other clips. There is also a small hole for the lanyard that comes with the case, to hang the case around my neck.

image courtesy Sea to Summit

The map case is easily folded and is described on the packaging as being freeze proof, crease resistant, and resistant to degradation due to UV exposure, as well as water and dust proof. The seal is a Ziploc® seam along one end of the bag. The seal appears to be fairly strong once I work the two sides together with my fingers. I can find no flaws, upon completing my initial inspection of the map case.

Initial Report

I have a lot of maps of all sizes, and it's fairly easy for me to fold them to fit in the case. Some of the larger ones make bulkier parcels than I like. This is the medium version of the case; I could fit 8.5 x 11" (216 x 279 mm) pages inside without folding.

The pliable nature of the case makes it easy for me to roll the map and case to stow in a side pocket of my pack. I inserted a map and zipped the case most of the way shut, then forced the rest of the air out of the case before sealing. This resulted in a nice flat case with my map inside, folded so that the relevant section for the trip (hypothetically) was visible through the case.


Field Conditions

Point Reyes National Seashore, California, USA, January 13 - 15. Temperature Range: 40 to 70 F (4 to 21 C)

Dewey Point, Yosemite National Park, California, USA, February 4 - 5. Temperature Range: 15 to 55 F (-9 to 13 C)

Mariposa Grove, Yosemite National Park, California, USA January 29. Temperature Range: 45 to 55 F (7 to 13 C)

Search and Rescue Training, Huntington Lake, California, USA, February 17 - 19. Temperature Range: 20 - 45 F (-6 to 7 C)

Map and compass class, Woodward Park, Fresno, California, USA, February 26. Temperature Range: 50 to 60 F (10 to 16 C)

Henry Coe State Park, California, USA, March 3 - 4. Temperature Range: 38 to 60 F (3 to 16 C)

Panoramic Point, Kings Canyon National Park, California, USA, March 10. Temperature Range: 45 to 55 F (7 to 13 C)

Search and Rescue Training, Fresno, California, USA, March 18. Temperature: 55 F (13 C)

Field Report

I used the map case to protect my maps on nearly all my dayhikes, backpacking trips, and trainings during the past two months. I have used it in rain and snowfall, and in colder temperatures down to 15 F (-9 C).

On all occasions the map case kept my maps dry. Most of the time I take a custom map printed from map software, and don't use special waterproof paper. I also used the map case with commercially printed maps by refolding the map so it fit in the case. I've put my wilderness permit in it as well as the campfire permit to keep that paperwork from getting wet.


The case shows very little indication that it's been rolled, folded, stuffed or smashed into my pack, though it has been subjected to all those. The clear plastic is still pliable and clear, and the seal is still strong. The cold doesn't seem to have affected the plastic.

I have been able to use an interpolator without taking the map out of the case. While on a mock search in a downpour, we used the case to house the map provided to our search team and were able to shake off raindrops as necessary. On our winter training my team snowshoed around our area in a light snowfall and had no issues with the map case.

On occasion when taking the map out to switch pages or to refold a larger map, I noticed that in colder temperatures, the clear plastic can cling and require me to insert my hand into the case to part the sides, so I can adjust or remove the map pages. Regular paper tends to cling to the plastic as well; the commercial maps with waterproofed paper cling less.


Field Conditions

Henry Coe State Park, Morgan Hill, California, USA, March 30 - April 1. Temperature Range: 40 - 60 F (4 - 15 C)

Pinnacles National Monument, Paicines, California, USA, April 27 - 28. Temperature Range: 45 - 75 F (7 - 24 C)

Laurel Lake, Yosemite National Park, California, USA, May 5 - 6. Temperature Range: 45 - 80 F (7 - 27 C)

Kibbie and Eleanor Lakes, Yosemite National Park, California, USA, May 26 - 28. Temperature Range: 30 - 52 F (-1 - 11 C)

Long Term Report

This past couple of months I've seen quite a bit of rain - one whole day hiking in ongoing rain at Henry Coe State Park, and in snow and rain in Yosemite National Park over Memorial Day weekend (May 26 - 28). I've also had the map case out in freezing temperatures again.

The map case has protected my wilderness permits, maps printed on plain white paper, and folded commercial maps. The case continues to be pliable, clear (not discolored due to UV exposure), and the seal is still strong and waterproof. I've had the case rolled or folded most of the time and it has ridden under the straps on the outside of the pack quite a bit.

I anticipate I will be continuing to take the map case with me on searches to protect the printed maps we are provided, and on leisure backpacking trips when variable weather conditions are expected.


I have found the Sea to Summit TPU Guide Map Case a great addition to my pack. I have found it adequately protects my important papers and maps in inclement weather, even when carrying it on the outside of the pack.

My thanks to Sea to Summit and BackpackGearTest for the opportunity to review the TPU Guide Map Case.

Read more reviews of Sea to Summit gear
Read more gear reviews by Lori Pontious

Reviews > Navigation and Map Gear > Accessories > Sea to Summit TPU Map Case > Test Report by Lori Pontious

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