What natural substance found in wool helps protect it from moths?
- Astringent
- Mordant
- Grease
- Tannin
Correct Answer: Grease
Correct Answer Explanation: The natural grease found in wool acts as a protective layer, preventing moths from damaging the fibers. This grease should be retained until dyeing, as washing it out exposes the wool to moth damage.
What is the name of the chemical bridge that binds dye to the fiber, making the color permanent?
- Astringent
- Mordant
- Substantive Dye
- Tannin
Correct Answer: Mordant
Correct Answer Explanation: Mordants are crucial for achieving both fast and brilliant colors with natural dyes. They act as a chemical bridge between the dye and the fiber, influencing the final color.
Which of these dyes colors cotton directly, without the need for a mordant?
- Logwood
- Indigo
- Turmeric
- Madder
Correct Answer: Turmeric
Correct Answer Explanation: Turmeric is a substantive dye, meaning it colors cotton directly without the need for a mordant. It yields vibrant orange-yellow hues.
Which of these plants produces a brown dye when used fresh and unoxidized?
- Alder bark
- Oak bark
- Walnut husks
- Peat soot
Correct Answer: Walnut husks
Correct Answer Explanation: Walnut husks are used for dyeing brown. It is important to use them fresh and unoxidized to achieve the desired color.
What is the traditional use of alder bark in dyeing?
- Yellow dye
- Red dye
- Brown dye
- Black dye
Correct Answer: Brown dye
Correct Answer Explanation: Alder bark has been traditionally used for dyeing brown. With the addition of copper sulfate, it produces black.
What is the name of the process that involves deoxidizing indigo to create a soluble form for dyeing?
- Scouring
- Saddening
- Indigo Vat
- Greening
Correct Answer: Indigo Vat
Correct Answer Explanation: The Indigo Vat process is a complex and crucial step in dyeing with indigo. It involves reducing indigo to a soluble form through a chemical process, requiring careful preparation and maintenance of the vat.
Which of these is a more stable alternative to the hydrosulphite indigo vat?
- Zinc-lime indigo vat
- Turkey Red process
- Woad vat
- Madder vat
Correct Answer: Zinc-lime indigo vat
Correct Answer Explanation: The Zinc-lime indigo vat is a more stable alternative to the hydrosulphite vat. It is less affected by temperature fluctuations and can be reused after a long period of rest.
Which of these natural dyes was banned by Queen Elizabeth I?
- Logwood
- Indigo
- Woad
- Madder
Correct Answer: Logwood
Correct Answer Explanation: Queen Elizabeth I banned logwood due to its perceived instability and unreliability as a dye. However, it eventually found renewed use for black and purple dyes.
What is the name given to the process of adding a yellow dye to blue-dyed wool to achieve a green color?
- Scouring
- Saddening
- Indigo Vat
- Greening
Correct Answer: Greening
Correct Answer Explanation: Greening is a technique used to achieve green colors by adding a yellow dye to blue-dyed wool. It is a common practice in natural dyeing to create various shades of green.
Which of these is NOT a mordant traditionally used in dyeing?
- Alum
- Iron
- Chrome
- Tin
- Copper
Correct Answer: Tin
Correct Answer Explanation: While alum, iron, chrome, and copper are all commonly used mordants, tin is not traditionally used as a mordant in dyeing.
Which of these natural dyes was considered the primary red dye in the Middle Ages?
- Woad
- Madder
- Kermes
- Logwood
Correct Answer: Kermes
Correct Answer Explanation: Kermes was the primary red dye in the Middle Ages, prized for its vibrant and lasting colors. It was used extensively in tapestries and textiles until the discovery of cochineal scarlet in the 17th century.
What is the name of the natural dye derived from tree bark, commonly used for dyeing brown, grey, and black?
- Madder
- Cutch
- Logwood
- Fustic
Correct Answer: Cutch
Correct Answer Explanation: Cutch, also known as Catechu, is a powerful dye for cotton, offering a rich and permanent color. It is used for various shades of brown, grey, and black.
Which of these natural dyes produces the most brilliant and lasting green color when combined with indigo?
- Weld
- Madder
- Fustic
- Logwood
Correct Answer: Weld
Correct Answer Explanation: Weld is known for its bright and permanent colors, making it a sought-after dye for both wool and silk. It is often used in combination with indigo to create the most brilliant and lasting green colors.
Which of these dyes is known for its vibrant and lasting colors, making it a valuable dye for both wool and silk?
- Weld
- Fustic
- Madder
- Logwood
Correct Answer: Weld
Correct Answer Explanation: Weld is prized for its bright colors and permanence, making it a sought-after dye for both wool and silk.
What is the name of the intricate and time-consuming dyeing process used to achieve Turkey Red?
- Indigo Vat
- Turkey Red process
- Woad Vat
- Madder Vat
Correct Answer: Turkey Red process
Correct Answer Explanation: The Turkey Red process is a complex and intricate method used to achieve vibrant and lasting red colors on cotton. It involves a series of steps, including mordanting with oil and alum, and dyeing with madder root.
What is the approximate percentage of tannic acid found in divi-divi?
- 10%
- 20%
- 30%
- 40%
Correct Answer: 20%
Correct Answer Explanation: Divi-divi is a natural source of tannic acid, a compound often used as a mordant in dyeing. It typically contains around 20% tannic acid.
What is the approximate percentage of tannic acid found in myrobalans?
- 10%
- 20%
- 30%
- 40%
Correct Answer: 25-40%
Correct Answer Explanation: Myrobalans are another natural source of tannic acid, known for their high tannic acid content, ranging from 25% to 40%.
What is the approximate percentage of tannic acid found in valonia?
- 10%
- 20%
- 30%
- 40%
Correct Answer: 25-35%
Correct Answer Explanation: Valonia is a natural source of tannic acid, often used as a mordant in dyeing. It typically contains around 25-35% tannic acid.
What is the typical percentage of indigo in a 20% indigo paste?
- 10%
- 20%
- 30%
- 40%
Correct Answer: 20%
Correct Answer Explanation: A 20% indigo paste typically contains 20% indigo by weight.
What is the typical capacity of a dye vat for cotton and linen using the Zinc-lime indigo process?
- 5 gallons
- 10 gallons
- 15 gallons
- 20 gallons
Correct Answer: 15-20 gallons
Correct Answer Explanation: A dye vat for cotton and linen using the Zinc-lime indigo process typically has a capacity of 15-20 gallons.
What is the minimum temperature required for the initial mixing of indigo and zinc dust in the Zinc-lime indigo vat?
- 100°F
- 120°F
- 140°F
- 160°F
Correct Answer: 160°F
Correct Answer Explanation: The initial mixing of indigo and zinc dust in the Zinc-lime indigo vat requires a minimum temperature of 160°F to ensure proper reduction of indigo.
What is the optimal temperature range for the stock vat in the Zinc-lime indigo process?
- 100-120°F
- 120-140°F
- 140-160°F
- 160-180°F
Correct Answer: 120-140°F
Correct Answer Explanation: The optimal temperature range for the stock vat in the Zinc-lime indigo process is 120-140°F, ensuring proper reduction of indigo and maintaining the vat’s stability.
What is the ideal starting temperature for the dye vat in the Zinc-lime indigo process?
- 50-60°F
- 60-70°F
- 70-80°F
- 80-90°F
Correct Answer: 65-70°F
Correct Answer Explanation: The ideal starting temperature for the dye vat in the Zinc-lime indigo process is 65-70°F, ensuring consistent dyeing results and preventing the vat from becoming too hot.
What is the approximate amount of weld used to dye silk yellow?
- 50%
- 75%
- 100%
- 150%
Correct Answer: 150%
Correct Answer Explanation: To achieve a vibrant yellow color on silk, a higher amount of weld is used compared to other fibers. The author suggests using approximately 150% of the weight of the silk in weld.
What is the approximate amount of madder used to dye silk red?
- 50%
- 75%
- 100%
- 150%
Correct Answer: 100%
Correct Answer Explanation: To achieve a vibrant red color on silk, the author recommends using an amount of madder that is equal to the weight of the silk.
What is the approximate amount of fustic used to dye silk yellow?
- 50%
- 75%
- 100%
- 150%
Correct Answer: 50%
Correct Answer Explanation: Fustic is another natural dye used for yellow. The author suggests using approximately 50% of the weight of the silk in fustic to achieve a desirable yellow color.
What is the approximate weight of a long woolled sheep fleece?
- 6 lbs
- 8 lbs
- 10 lbs
- 12 lbs
Correct Answer: 12 lbs
Correct Answer Explanation: Long woolled sheep can produce fleeces that weigh up to 12 lbs.
What is the record length of a long woolled sheep fleece?
- 24 inches
- 30 inches
- 36 inches
- 42 inches
Correct Answer: 36 inches
Correct Answer Explanation: The record length of a long woolled sheep fleece is 36 inches, showcasing the remarkable length and quality of wool from certain breeds.
What is the process called that involves washing wool or other fibers to remove impurities and grease?
- Saddening
- Scouring
- Greening
- Mordanting
Correct Answer: Scouring
Correct Answer Explanation: Scouring is a crucial step in preparing fibers for dyeing. It involves thoroughly washing the fibers to remove impurities, grease, and other substances that can interfere with the dyeing process.
What is the name of the process that involves using a mordant to darken or modify a dye color?
- Scouring
- Saddening
- Greening
- Mordanting
Correct Answer: Saddening
Correct Answer Explanation: Saddening is a technique used to darken or modify a dye color by using a mordant. It can be applied to various dyes and fibers, adding depth and complexity to the final color.
What is the name given to the astringent compound found in plants, often used as a mordant in dyeing?
- Tannin
- Mordant
- Astringent
- Substantive Dye
Correct Answer: Tannin
Correct Answer Explanation: Tannin is a naturally occurring astringent compound found in various plants. It is often used as a mordant in dyeing, helping to strengthen the bond between the dye and the fiber, adding brilliance to the colors.
What is the traditional use of bracken in dyeing?
- Red dye
- Brown dye
- Grey dye
- Yellow dye
Correct Answer: Grey dye
Correct Answer Explanation: Bracken is a plant traditionally used for dyeing grey, highlighting the diverse range of dyeing possibilities with different plants.
What is the traditional use of lichen in dyeing?
- Red dye
- Brown dye
- Grey dye
- Yellow dye
Correct Answer: Brown dye
Correct Answer Explanation: Lichen is a versatile dye, commonly used for achieving various shades of brown. It is a natural source of color, offering a range of earthy tones.
What is the distinctive smell of Harris tweed partially attributed to?
- Wool grease
- Crottle
- Indigo
- Madder
Correct Answer: Crottle
Correct Answer Explanation: Harris tweed’s distinctive smell is partially attributed to the use of crottle, a lichen dye, in its production. This traditional dyeing practice adds a unique character to the fabric.
What is the reason behind silk requiring stronger indigo vats and longer dips than wool to achieve the same depth of color?
- Silk is more porous
- Silk is less absorbent
- Silk is stronger
- Silk is finer
Correct Answer: Silk is finer
Correct Answer Explanation: Silk fibers are finer than wool fibers, making them more difficult to dye. Stronger indigo vats and longer dips are needed to achieve the same depth of color on silk, as the dye needs to penetrate the finer fibers.
What is the process called that involves treating silk with soap to remove its natural gum?
- Scouring
- Saddening
- Greening
- Mordanting
Correct Answer: Scouring
Correct Answer Explanation: Scouring is a crucial step in preparing silk for dyeing. It involves removing the natural gum present on silk fibers, which can interfere with the dyeing process.