What Is Burlap?

How is burlap made?

Burlap is made by soaking the stems of the jute plant (or hemp) to free the fibre, spinning that fibre into a coarse yarn and weaving it in a plain weave, with each thread passing over one and under the next.

From plant to fibre

Jute comes from the inner bark, or bast, of two plants, Corchorus olitorius and Corchorus capsularis. It is an annual crop that takes about 120 days to grow, sown in April or May and harvested in July or August.

The fibre is released by retting. In biological retting, bundles of stems are soaked in water until the fibres loosen; the stack, steep and ribbon methods are variations on this. Chemical retting is the alternative. Workers then strip the stems, scraping away the non-fibrous matter and pulling the fibres out.

The strands are long. The UN Food and Agriculture Organization (FAO) gives a length of 1 to 4 m and a diameter of 17 to 20 microns, while the Museum of Fine Arts, Boston's materials database gives 1.5 to 3.0 m. Sources differ, so treat any single figure as approximate.

From fibre to cloth

Plain weave gives burlap its open, checkerboard grid of threads, quite different from the diagonal ribs of a twill. Sacking still makes up the bulk of manufactured jute products.

What is the difference between burlap, jute, hessian and linen?

Jute is the fibre, burlap is the cloth woven from it (or from hemp), hessian is the British name for the same cloth, and linen is a different cloth made from the flax plant.

Burlap is also often mistaken for canvas. The two are different cloths; burlap's coarse, open grid is the clearest visual difference.

What are the properties of burlap?

Burlap is strong, stiff, breathable and coarse, but it loses much of its strength when wet and breaks down in sunlight, damp and age.

• Strength and stretch: jute has high tensile strength and low extensibility, so the cloth resists tearing and barely stretches.
• Breathability: jute makes breathable fabrics, and it is used extensively for sacking agricultural goods.
• Look and hand: the raw fibres are pale brown, lustrous and coarse; the FAO describes their golden, silky shine.
• Moisture: jute has a moisture regain of 13.75%, meaning it takes up water equal to about 13.75% of its dry weight under standard conditions.
• Wet strength: jute becomes so weak when wet that a thin jute twine can be broken by hand.
• Ageing: it has poor resistance to sunlight, microorganisms and insects, and turns brown and degrades over time.

Treating jute with caustic soda improves its crimp, softness and pliability, which helps it to be spun with wool.

How is burlap graded or measured?

Burlap is graded by its weight per square metre and by its thread count, given as ends (warp threads) and picks (weft threads) per decimetre.

The Indian Standard for hessian, IS 2818 (Part III), shows how this works for the two types it specifies:

Two details matter when comparing. First, these weights are stated at a contract moisture regain of 16%, because jute absorbs water and a damp bale weighs more. Second, the older trade figure ties ounces to a 40-inch width, so it is not the same unit as grams per square metre. Compare like with like.

How does burlap appear on a clothing label?

Burlap never appears on a fibre label, because it is a cloth name; the label names the fibre, usually "jute".

• In the EU: only the fibre names listed in Regulation (EU) No 1007/2011 may describe fibre composition. Jute is listed by that name, hemp appears as "true hemp", and flax as "flax (or linen)". A product may be called "100%", "pure" or "all" only if it is made exclusively of one fibre.
• In the US: natural and man-made fibres must be identified by their generic names, listed by percentage of weight in descending order. Fibres under 5% are generally grouped as "other fiber".
• The bag exception: the US Federal Trade Commission lists tote bags and the textiles used in handbags among products the Textile Act does not cover. A burlap tote bag or handbag can therefore be sold in the US with no fibre-content label at all.

How do you tell good burlap from poor burlap?

Good burlap has an even, dense grid of threads, a stated weight in grams per square metre, a pale brown colour with some lustre, and fibres that flex without cracking.

1. Count the threads. Lay a ruler on the cloth and count threads across 1 cm each way. The lighter IS 2818 grade has about 4 ends and 3 picks per centimetre; the heavier one about 5 each way. A denser count means a heavier, firmer cloth. Look for gaps where the grid opens up unevenly.
2. Read the weight. A seller who gives grams per square metre gives you something to compare. A figure in ounces without a width tells you little.
3. Look at the colour. Fresh jute is pale brown and slightly lustrous. Because jute turns brown and degrades with age, cloth that is dark, dull and dry-looking may be old stock.
4. Flex a fold. Bend a corner sharply and rub it. Jute fibres are naturally brittle, but cloth that cracks along the fold or sheds broken fibres has weakened.
5. Smell and check for spots. Jute resists microorganisms poorly, so a musty smell or dark speckling may point to damp storage.
6. Read the percentages. A soft "jute" cloth for clothing may be a blend. Under EU rules it can only say "100% jute" if it is jute alone.

How do you care for burlap?

Keep burlap dry, clean it by brushing or spot-cleaning rather than soaking, and store it away from sunlight and damp.

The reasons are the fibre's weak points. Jute loses strength sharply when wet, so long soaks and wringing put the most strain on the cloth just when it is weakest. If a spot clean gets it damp, let it dry flat and fully before storing. Jute's poor resistance to sunlight, microorganisms and insects means a dark, dry, ventilated cupboard is the best home for a burlap bag out of season. Always follow the care label where there is one.

Is burlap sustainable?

Jute, the main fibre in burlap, is a low-input crop by the FAO's account, but how sustainable a given piece of burlap is depends on how it was retted, processed and finished, which a label does not show.

The FAO describes jute as a rain-fed crop with little need for fertiliser or pesticides, and as 100% biodegradable and recyclable. It also states that a hectare of jute plants takes up about 15 tonnes of carbon dioxide and releases 11 tonnes of oxygen. These are claims about the plant and the raw fibre, not about a finished product with dyes, coatings or mixed fibres.

Production is concentrated. According to the FAO's Future Fibres profile, which is undated, about 95% of the world's jute is grown in India and Bangladesh, which account for roughly 60% and 30% of output. Retting, which usually means soaking bundles of stems in water, is one processing stage that no fibre label in the EU or US records. For the wider picture, see sustainable fashion.