The word canvas is derived from the 13th century Anglo-French canevaz and the Old French canevas. Both may be derivatives of the Vulgar Latin cannapaceus for “made of hemp,” originating from the Greek κάνναβις (cannabis).
Properties of Hemp
As the premier plant fiber, True Hemp or Cannabis sativa has served mankind for thousands of years. This venerable fiber has always been valued for its strength and durability. Materials made from hemp have been discovered in tombs dating back to 8,000 B.C.E. Christopher Columbus sailed to America on ships rigged with hemp. Hemp was grown extensively in colonial America by numerous farmers including George Washington and Thomas Jefferson. Betsy Ross sewed the first American flag from hemp. In fact, its combination of ruggedness and comfort were utilized by Levi Strauss as a lightweight duck canvas for the very first pair of jeans made in California.
For thousands of years hemp was traditionally used as an industrial fiber. Sailors relied upon hemp cordage for strength to hold their ships and sails, and the coarseness of the fiber made hemp useful for canvas, sailcloth, sacks, rope, and paper.
While hemp fiber was the first choice for industry, the coarseness of the fiber restricted hemp from apparel and most home uses. Hemp needed to be softened. Traditional methods to soften vegetable fibers used acids to remove lignin, a type of natural glue found in many plant fibers. While this method to remove lignin worked well with cotton or flax, it weakened the fibers of hemp and left them too unstable for use. Hemp therefore remained as an industrial fabric.
In the mid 1980’s, researchers developed an enzymatic process to successfully remove lignin from the hemp fiber without compromising its strength. For the first time in history, de-gummed hemp fiber could be spun alone or with other fibers to produce textiles for apparel. This technological breakthrough has catapulted hemp to the forefront of modern textile design and fashion. Given hemp’s superiority to other fibers, the benefits of this breakthrough are enormous.
Hemp fiber is one of the strongest and most durable of all natural textile fibers. Products made from hemp will outlast their competition by many years. Not only is hemp strong, but it also holds its shape, stretching less than any other natural fiber. This prevents hemp garments from stretching out or becoming distorted with use. Hemp may be known for its durability, but its comfort and style are second to none. The more hemp is used, the softer it gets. Hemp doesn’t wear out, it wears in. Hemp is also naturally resistant to mold and ultraviolet light.
Due to the porous nature of the fiber, hemp is more water absorbent, and will dye and retain its color better than any fabric including cotton. This porous nature allows hemp to “breathe,” so that it is cool in warm weather. Furthermore, air which is trapped in the fibers is warmed by the body, making hemp garments naturally warm in cooler weather.
Hemp is an extremely fast growing crop, producing more fiber yield per acre than any other source. Hemp can produce 250% more fiber than cotton and 600% more fiber than flax using the same amount of land. The amount of land needed for obtaining equal yields of fiber place hemp at an advantage over other fibers.
Hemp grows best in warm tropical zones or in moderately cool, temperate climates, such as the United States. Hemp leaves the soil in excellent condition for any succeeding crop, especially when weeds may otherwise be troublesome. Where the ground permits, hemp’s strong roots descend for three feet or more. The roots anchor and protect the soil from runoff, building and preserving topsoil and subsoil structures similar to those of forests. Moreover, hemp does not exhaust the soil. Hemp plants shed their leaves all through the growing season, adding rich organic matter to the topsoil and helping it retain moisture. Farmers have reported excellent hemp growth on land that had been cultivated steadily for nearly 100 years.
As a fabric, hemp provides all the warmth and softness of a natural textile but with a superior durability seldom found in other materials. Hemp is extremely versatile and can be used for countless products such as apparel, accessories, shoes, furniture, and home furnishings. Apparel made from hemp incorporates all the beneficial qualities and will likely last longer and withstand harsh conditions. Hemp blended with other fibers easily incorporates the desirable qualities of both textiles. The soft elasticity of cotton or the smooth texture of silk combined with the natural strength of hemp creates a whole new genre of fashion design.
The possibilities for hemp fabrics are immense. It is likely that they will eventually supersede cotton, linen, and polyester in numerous areas. With so many uses and the potential to be produced cheaply, hemp textiles are the wave of the future! (SOURCE: http://www.hemptraders.com )
WHAT ABOUT HEMP CANVAS?
In 2004 I made my first Hemp Tipi, in response to my growing awareness of the toxicity of the treated cotton canvas which I had been using exclusively since I began making Tipis in 1997. I had become especially concerned about the flame-resistant chemicals in this canvas.
I discovered in my research that the whole cotton industry is one of THE most toxic industries on the planet! (In the top 5). The cultivation of cotton requires enormous quantities of toxic chemicals, in the form of pesticides, herbicides, fungicides and fertilizers. This cotton is sourced from India, so in order for me to provide a cotton canvas Tipi to you, the soil, air, water and people in India are being polluted. Not only that, the finished canvas is then imported to Georgia, where it goes to the “finishing plant” to be “treated” with another array of toxic chemicals to provide a canvas that is resistant to water, mildew and fire. Again, the soil, air, water and people are being exposed to this pollution. And then in order to turn the canvas into a Tipi, I am also exposed to these chemicals while I work. And then the question arises......how does this affect the folks who use the Tipi? These facts and questions were the main motivators in my seeking a more Environmentally-friendly canvas. In researching Hemp fiber, I discovered its remarkable qualities and felt it was a promising alternative. I now have 10+ years experience using this fabric for Tipis, and the results are mixed.
Foremost, I absolutely LOVE working with Hemp! It is beautiful, easy to handle and makes a superior Tipi. The quality of light that you experience inside a Hemp Tipi is so ALIVE compared to the treated cotton. However, it is not suitable for certain climate conditions, unless treated and painted.
Hemp is highly absorbent but mildew resistant. What happens when the Hemp Tipi gets rained on? The fibers immediately swell up, making the canvas tight so that it sheds the rain. It does feel damp to the touch, but the rain does not leak through. This is great! But it can be troublesome if you have bedding, clothing or books touching up against the Tipi wall or liner, because the moisture will “wick”, or transfer to your stuff. It's not so much of a concern if you are in a dry climate and rain comes infrequently. The Hemp dries out quickly when the source of moisture goes away, & it's easy to keep your things a few inches away from contact with the canvas. However, in a high-humidity environment the Hemp doesn't have much chance to completely dry out, and although it is known to be “naturally mildew-resistant”, if it is under constant exposure to moisture it will begin to mildew, especially where it is in contact with the poles.
This dilemma led me to search for a non-toxic way to treat the Hemp canvas to repel water. I found “CottonProof®”, sold by a company called NikWax. It is a liquid concentrate that you dilute with warm water and apply to the dry canvas, best applied with a long-handled paint roller. This is done outdoors during warm, dry weather, with the Tipi cover/liner/door spread out flat on large tarps. An 18-foot cover takes 2 people about 2 hours to treat. The canvas is then left to air-dry for a day and it is done. I recommend following with a thinned (50/50 with water) coat of exterior latex paint, within one year. Otherwise, you need to re-apply the treatment again in 4 years.
The other major influence on the viability of Hemp as a Tipi fabric is the effect of UltraViolet rays. Indeed, I consider this to be the main impact on the life expectancy of a Tipi, whatever fabric is used. So, unless your Lodge is made from PVC-coated polyfiber, (which I don't offer), it is going to be impacted by the sun. In fact, I have heard a significant increase in feedback about UV deterioration in the past year, coming from customers who purchased Tipis in 2010/2011. This was not limited to those who purchased Hemp. Is our atmosphere changing? Has the fabric quality diminished? I can't make any declarations here, but something's up. The “normal life expectancy” of a Tipi has been lessened for some reason. Case in point: My personal Tipi was made in early 2002, which means 13 “seasons” of use, to date (2/15). Two years ago it began to show signs of UV damage. This Lodge has gotten very heavy use, put up and taken down multiple times per season and left up all thru the winter months two times. Aside from a repair due to a young deer who ventured inside and then kicked its way out, the canvas has held up remarkably well. This was made from 10-ounce Sunforger, a lighter weight than I use nowadays. Tipis made from this weight of canvas can now be expected to last only 5 to 7 years. I now use only 12.65-ounce Sunforger Marine. ( & Only non-fire-resistant, after finding out that the FR chemicals increase the rate of UV damage).
All these factors can be addressed with one solution. To prolong the life of the canvas, whether Hemp or Sunforger, give it a coat of very thinned exterior latex paint. This is the best protection from UV rays, mildew and water. It will also help you develop a closer relationship with your Lodge.
*The liner is highly prone to rot along the bottom where it contacts the ground. This is true even for treated cotton, so I always recommend a thinned (50/50) coat of exterior latex paint on the lower 12” to 18” of the liner. This simple step will significantly prolong the life of the liner.
*The poles should also be treated if you live in a damp area, even if you have a treated cotton Tipi. In damp conditions, untreated poles will begin to mildew and transfer that mildew over to the canvas wherever they contact. This will also help retain the beautiful color of freshly peeled poles. I use HempShield® Deck Oil, which is easily applied with a fleecy paint-mitt from the hardware store.