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Reviews > Clothing > Base Layers and Undies > Coldpruf Eco Terra Base Layers > Test Report by Ryan Lane Christensen

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ECO-TERRA Base Layer

Test Series by
Ryan Christensen

Last Update - May 20, 2012

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January 5, 2013
March 19, 2013
May 20, 2013

January 5, 2013

Reviewer Information Backpacking Background
Name:  Ryan L. Christensen
Age:  48
Gender:  Male
Height:  6 ft 2 in (1.88 m)
Weight:  235 lb (107 kg)
Email:  bigdawgryan(at)yahoo(dot)com
City, State, Country:   Idaho Falls, Idaho, USA

I began backpacking at twelve, continuing until 25. After an extended hiatus, due in part to a bad back, I resumed cycling, hiking, and backpacking several years ago. I also began snowshoeing and cross-country skiing. I share my love for backpacking and these sports with my children. I am a midweight backpacker, but carry a full array of necessary gear.

Product Information:

The information below came from COLDPRUF's website and ECO-TERRA product packaging.

ECO-TERRA Base Layers
Manufacturer: COLDPRUF Base Layer
Manufacturer website:
Place of Manufacture: Mexico (from U.S. components)
Year Manufactured: 2012
Materials: 70% Recycled Performance Polyesters, 30% Merino Wool
Sizes Available: Small, Medium, Large, XL, 2XL, 3XL (in both regular and tall)
Tall Tops: 2 in (5 cm) longer and 1.5 in (3.8 cm) longer sleeves
Tall Bottoms: 3 in (7.6 cm) longer
Colors Available: single color
MSRP: Top: N/A
Bottom: N/A

Product Specifications
Manufacturer's Specifications  
Weight: N/A
Tester's Actual Measurements
Weight: 2XL Top: 11.3 oz (320 g)
2XL Bottom: 10 oz (284 g)

Product Description:

The ECO-TERRA is a polyester/wool blend midweight performance baselayer. The ECO-TERRA, only available in men's sizes, is one of two products which comprise the ECO line. Using Thermachoice®, COLDPRUF's simple color-coding system that combines temperature rating and activity level, the ECO-TERRA is classified for use in Cold to Extreme Cold conditions and Low to High Activity levels. COLDPRUF ECO utilizes polyester staple fiber produced from recycled waste PET bottles (such as those used for soft drinks). This recycled polyester fiber is blended with merino wool for use in the ECO-TERRA. However, the percentage of merino wool is somewhat low to help minimize the risk of overheating. During the manufacturing process, the ECO-TERRA fabric is treated with Microban® antimicrobial to help prevent the growth of odor-causing bacteria.

Both the top and bottom are single-layer raschel knit fabric which resembles hand-crocheted fabric and lace. Raschel knit is a form of warp knitting (multiple parallel yarns looped vertically at the same time to form parallel ridges running lengthwise through the material). Warp knit fabric is claimed to have greater dimensional stability, sag less, and ravel less easily than weft knit (single yarn used to form horizontal rows of looped stitches) materials. The fabric is somewhat stretchy. It will be interesting to see how well this material holds it shape and stays in place.

2XL Top:

The top has what I consider to be a narrow-collared crew neck (0.5 in or 1.3 cm). It has flat, overlocked seams extending from the crew neck across the top of the shoulder, where the sleeve meets the shoulder, along the underside of each sleeve, down both sides of the torso, and along the hem. The sleeves (from shoulder seam to end of cuff) are approximately 25 in (64 cm) in length. The ribbed cuffs are approximately 2.75 in (7 cm) in length. The tail of the top extends 2.5 in (6.4 cm) longer than the front; with the overall length (collar to bottom of tail) being approximately 32 in (81 cm). There is no tag inside the shirt. Rather, there is a silk-screened label inside, on the back, near the collar. The label includes the COLDPRUF ECO logo, material, size, and laundering information.

2XL Bottom:

Like the top, the bottom has flat, overlocked seams. These seams form the fly and the gusseted crotch, run down the inside of each leg, and around both of the ribbed cuffs. The bottom has an elastic waistband, which is approximately 1.25 in (3.2 cm) in width. There is a silk-screened label inside, on the back, near the waistband. The label includes the COLDPRUF ECO logo, material, size, and laundering information. From the top of the waistband to the bottom of the ribbed cuff, they are approximately 43 in (109 cm) in length. The ribbed cuffs are approximately 2.5 in (6.4 cm) in length.

COLDPRUF® Base Layer manufacturers nine product lines:

  • ECO
Each of COLDPRUF's product lines is intended for use in specific temperature ranges and activity levels.

CARE INSTRUCTIONS: (same for top and bottom)

  • Machine wash warm, with like colors
  • Use only non-chlorine bleach when needed
  • DO NOT use fabric softener (sheet or liquid)
  • Use of fabric softeners will impede antimicrobial properties
  • Tumble dry low, remove promptly
  • Low iron if needed

Initial Impression:

The first thing that caught my attention was the feel of the fabric. The polyester/merino wool blend fabric is soft to the touch, not scratchy like some wool fabric baselayers. I like the lace-like raschel knit and am anxious to see how well it breathes. The single-layer fabric is relatively thin; however, it feels more like a midweight baselayer than some of my other midweights. Although neither mentioned on the packaging nor the COLDPRUF website, I am anxious to see how these baselayer products wick moisture.

Initial Testing:

Initially I received only the 2XL top as requested, but no bottom. The Test Director contacted the manufacturer and I received a 2XL bottom a week or so later. However, based on my 38 in (97 cm) waist and COLDPRUF's size chart which lists their Large bottoms being for men with 36 - 38 in (91 - 97 cm) waists, I had requested a Large bottom. Once again, the Test Director contacted the manufacturer. After the Christmas holiday, I received the Large bottom. After removing the top and bottom baselayer items from their packaging, I proceeded to thoroughly examine them for any noticeable flaws. These baselayer products appear to be constructed of high quality material and workmanship. I did not find any loose seams or other noticeable defects in materials or workmanship.


Next, I donned the top to check sizing. The sleeves were long enough and fit nicely the entire length. The ribbed cuffs were snug, but not overly so. The top was not too tight through the chest/shoulder area. And, the tail length appears to be sufficient to keep it from riding up. The fit and feel of the fabric next to my skin was quite comfortable. I really like the fact that the top does not have any tags in it.


Next, I donned the Large bottom. Although COLDPRUF's website states "TRUE SIZING FOR ACCURATE FIT" related to its sizing as indicated by the line drawn to the thigh area (as shown in the photos at the top of this report), much to my chagrin, the bottoms did not fit me. The Large was so tight in the calves, but especially in the thighs, that I could not pull the bottom up fully. I was disheartened to have followed the manufacturer's suggested sizing only to have the bottom be too small for me in the thighs. I do not consider myself as having overly large calves or thighs. Nevertheless, I took the Large bottom off, opened the 2XL bottom, and donned it. The 2XL bottom fit nicely in the legs, and overall length. The ribbed cuffs were snug, but not overly so. However, for me, the 2XL bottom is quite oversized in the waist. The COLDPRUF sizing chart lists the 2XL bottom for men with 44 - 46 in (112 - 117 cm) waists--some 8 in (20 cm) larger than my waist. The waistband is stretchable enough that I believe the 2XL bottom will work for the test series. Although I would think an XL bottom would be a better overall fit for me. The feel of the fabric next to me skin was quite comfortable. I really like that the bottom does not have any tags in it.

Initial Pros:

Initial Cons:

  • made from recycled PET bottles
  • comfortable next to my skin
  • tagless
  • flat seams
  • antimicrobial
  • Men's Size Chart -- bottoms not true to my personal size

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March 19, 2013

Field Locations and Test Conditions:

I wore the ECO-TERRA baselayer top and bottom approximately 20 days in southeastern Idaho on 4 overnight cross-country ski outings, an overnight Boy Scouts of America Klondike Derby (winter campout), shoveling snow and kicking about during the test period. During this time period, we had approximately twenty or so sub-zero (-18+ C) days; the coldest being -21 F (-29 C) with wind gusts up to 20 mph (32 km/h) yielding a Wind Chill Index of -49.55 F (-45 C).

Eco-Terra The cross-country ski outings were in the Kelly Canyon Nordic Area, which is located 26 miles (42 km) northeast of Idaho Falls, Idaho in the Targhee National Forest. The Nordic Area starts at an elevation of approximately 5,900 ft (1,798 m) and reaches elevations of 6,700 ft (2,042 m). With poor early snowfall, the warming hut was not set up until the end of December. I only made one overnight trip in January, but got three more in during February. Typically we begin skiing to the warming hut about 8:00 p.m. MST (on Thursday nights after work). The temperature at the time we begin skiing in usually in the upper 20's (26 to 28 F or -3 to -2 C). My guess is that overnight low temperatures were generally in the low teens (12 to 14 F or -11 to -10 C). However, on one of the outings in February, temps were hovering around 0 F (-18 C).


Temperatures during this phase of the test have been crazy; the coldest being -21 F (-29 C) with wind gusts up to 20 mph (32 km/h) yielding a Wind Chill Index of -49.55 F (-45 C) and the warmest being 54 F (12 C). I only wore the ECO-TERRA baselayers when the temperature was below 30 F (-1 C). The ECO-TERRA performed well, especially on the colder days. Although I did not ski on the coldest days, I still had to shovel snow, go to work, etc. The baselayer did a fine job of keeping me warm. Even though it was only while walking from the parking lot to the building and back a couple of times that day, I was impressed with how warm they kept me when the wind chill index was -49.55 F (-45 C).

With the temperature generally in the upper 20's (26 to 28 F or -3 to -2 C) when we started skiing into the Kelly Canyon Nordic Area warming hut, I wore the merino wool/polyester performance baselayer under my ski jacket and softshell ski pants. I also wore a merino wool beanie and ski gloves with Thinsulate. After about ten minutes of skiing uphill, while carrying a 75L backpack, I unzipped both pit zips and the front zipper on my jacket to increase ventilation. After another ten minutes or so of skiing, I needed to shed the jacket altogether. It was just too warm! The ECO-TERRA baselayer top was sufficient during this highly aerobic activity. Once we arrived at the hut, I doffed the ECO-TERRA top so I could dry it out and donned a synthetic baselayer top and my jacket while we built a fire and gathered the fixings for our dinner. The jacket kept me comfortably warm while performing these camp chores. When we skied out in the mornings, I chose to wear a lighter weight softshell over the top of the ECO-TERRA baselayer top, which proved to be just right for the temperature and aerobic level.

The only issue I have had thus far has been that after wearing the merino wool/polyester performance baselayer top and bottom when engaged in highly aerobic activity, they felt a little scratchy, or itchy. Granted by this time, I'm hot and fairly sweaty. I have not had similar experience however, when wearing fully synthetic baselayers. Moreover, I have not had such itchy/scratchy feelings when wearing either socks or tops made from material with a higher percentage of merino wool. Not sure whether the cause of the itchy feeling I experienced is the blend or weave of the fabric. Although not unbearable, the itchy/scratchy sensation is a bit annoying to me.

I believe each night I arrived at the warming hut, I had a fair amount of frost on the front of the top, due to the moisture wicked from my body freezing. I believe this to be pretty good evidence that the ECO-TERRA baselayer does a good job wicking moisture away from my body. Both the ECO-TERRA baselayer top and bottom dried quickly when hung near the wood-burning stove.

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May 20, 2013

Field Locations and Test Conditions:

During the final phase of the test, I wore the baselayer top and bottom on three more overnight outings (primarily to sleep in). Two of these overnight outings were at Krupp Scout Hollow, a former 40-acre (160,000 m2) farm and orchard located in the town of Lorenzo, just north of Idaho Falls, Idaho. The temperature was generally in the upper 20's (26 to 28 F or -3 to -2 C).


The ECO-TERRA baselayer top and bottom kept me plenty warm on all outings during the final phase of the test series. In fact, on a couple of occasions, they were too warm for the activities I was engaged in, even sleeping. That could be due in part by the fact that I slept in either a 0 F (-18 C) or 15 F (-9 C) sleeping bag. Overall, I am very pleased with how well this polyester/wool blend midweight performance baselayer insulates, wicks moisture, and prevents malodor.

Although they did not smell bad, I laundered the ECO-TERRA baselayer top and bottom twice; once at the start of this test phase, and once after the last time I wore them. They laundered well; no noticeable pilling, loose or fraying seams, etc. They did not fade in color or shrink in size.

The only complaint I have about the ECO-TERRA baselayer continues to be how itchy/scratchy the bottom and top become next to my skin after a short period of time, especially if I am sweating. I wonder whether a greater amount of merino wool would remedy this problem. Nevertheless, I will likely keep these baselayer items in my gear stash. They will however serve as a backup to other synthetic blend baselayers I own, which for me, are more comfortable next to my skin.



  • made from recycled PET bottles
  • tagless
  • flat seams
  • antimicrobial
  • after time, they become itchy/scratchy next to my skin

This concludes my test series for the COLDPRUF ECO-TERRA baselayer top and bottom. Thanks to COLDPRUF and for allowing me to participate in this test series.

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Read more gear reviews by Ryan Lane Christensen

Reviews > Clothing > Base Layers and Undies > Coldpruf Eco Terra Base Layers > Test Report by Ryan Lane Christensen

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