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Responsibly made in Sweden, Woolpower is a collection of head to toe thermal undergarments available in different weights for use in varied temperatures for a variety of activities. The original Ulfrotte terry loop knit blends merino wool for warmth and synthetic fibres for durability. 100% manufactured in Östersund Sweden. these award winning garments are available in LITE, 200g/m², 400g/m², 600 g/m² and 800 g/m² material weights.

Natural Warming Technology

Merino wool is known as a very fine, soft, and crimpy fiber. It’s softness allows it to be worn comfortably against the skin as a natural warming insulator. As part of our eco-friendly philosophy, Woolpower’s unique material Ullfrotté Original uses Merino wool sourced from Mulesing-free Patagonian sheep. Ullfrotté Original is 22 microns, meaning the thickness of the wool fiber is 22 thousandths of a millimeter, resulting in not only durable but comfortable wool. LITE has a micron level of 19.5.

Woolpower US | Nature's Warming Fiber

Wool is nature’s own technical material and is the only natural fiber that man has been unable to synthetically replicate. It typically comes from sheep, but there are other types of wool including camel wool, mohair from the Angora goat, alpaca wool from the Alpaca, cashmere from the Cashmere goat, and angora from the Angora rabbit. Wool is considered our oldest textile material and has been used to make clothes for 10,000 years. It has been an important commodity signifying prosperity and power well into the 19th century.

Woolpower US | Natural Warming Technology

Counting Sheep

Today there are about a billion sheep all around the world, divided into more than 200 breeds. The largest producing regions are in Australia, New Zealand, and South America, with the most common breeds being Lincoln and Merino. Merino sheep produce exceptionally fine and crimpy wool. Merino sheep have their origins in North Africa, and most likely came to Spain near the end of the 12th century. The trade in this soft and fine wool was significant for Spain, which controlled the wool market for centuries, and for a long time banned the export of Merino sheep. The breed was named Merino in the 15th century after the royal sheep inspectors ‘los Merinos’.

Woolpower US | Natural Warming Technology


The crimped structure of wool fiber traps large quantities of air and provides superior heat insulation. Air between the fibers reduces the heat conduction within the material, and therefore has an insulating effect against both heat and cold. Merino wool can have up to 40 crimps per centimeter which provides a higher degree of insulation. The crimps in the fibers also mean that there are fewer contact points between the fibers and the skin making it more difficult for body heat to be released.

Natural Technology

Wet Wool Warms

During increased physical activity, the body generates perspiration in order to cool. Wool is hygroscopic, or able to absorb moisture from the air which means it can also control moisture vapor regulation. Wool fibers can absorb up to 30% of their dry weight before feeling damp. Wool also creates warmth when moist. When moisture is absorbed through wool, an exothermic process takes place. Heat energy is released when water and fiber molecules, which have opposite polarity, collide. The force of the collision is so intense that heat is created. The process continues until the fiber is saturated with water molecules.

Natural Technology

Wicky Wool

When humidity is higher inside the garment than outside, wool works hard to absorb the moisture and transport it through the material until equilibrium is reached. Moisture is transported to the outside of the garment enabling the inner layer to stay dry.

Natural Technology

Happily Hygenic

Wool is self cleaning and does not readily smell. Creatine, an organic acid in wool, naturally breaks down odor causing bacteria released from the skin. The core of the wool fiber consists of two types of cells that absorb different quantities of moisture. As a result, one type swells more than the other creating constant friction. This gives the wool fiber a mechanical, self-cleansing effect, essentially knocking bacteria off of the fiber. The surface of a wool fiber is also water repellent, which prevents bacteria growth and subsequent odors.

Natural Technology

Micron Magic

Microns are a unit commonly used to measure wool thickness and indicate quality. A micron is a thousandth of a millimeter. Fine wool is between 17 and 23 microns. The finer the fiber, the softer the feel of the material. Coarse fibers are in excess of 28 microns. Wool perceived as itchy is made of coarse fibers. These fibers do not yield to the skin, but rather penetrate.