NARRATOR:
You will hear a student discussing a textile design project with his tutor.
NARRATOR:
First, you have some time to look at questions 21 to 24.
NARRATOR:
Now listen carefully and answer questions 21 to 24.
TUTOR:
You wanted to talk about your textile design project?
JIM:
I have been investigating how natural dyes can color materials such as cotton and wool.
TUTOR:
What made you choose that subject?
JIM:
The textile exhibition at the museum gave me several useful ideas, and color has always interested me.
JIM:
But the first thing that really caught my attention was years ago when I visited a carpet shop in Turkey with my parents.
JIM:
The rugs had extraordinary colors.
TUTOR:
Some of those colors may have come from synthetic dyes.
JIM:
Once I had chosen the project, I found an excellent book about a Californian botanic garden that grows plants used in dyeing.
TUTOR:
Your project also needed a practical investigation.
JIM:
At first, I could not decide which variables to use.
JIM:
My original plan was to take one fiber, perhaps cotton, And test it with several dyes?
JIM:
Then I broadened the study and included wool and nylon as well as cotton.
TUTOR:
Were you still using only one dye?
JIM:
No, I used a variety, including a few synthetic dyes, so I could compare the results.
JIM:
I carried out the experiments last week.
JIM:
Some natural dyes were ready-made and arrived quickly from an online supplier, while I prepared others myself.
TUTOR:
That sounds time-consuming.
JIM:
I assumed I would need only a small spoonful of raw material.
JIM:
But I was completely wrong.
JIM:
For a red dye made from beetroot, I had to cut up a large heap of it.
JIM:
Preparing everything took far longer than expected.
TUTOR:
Food coloring is another option.
JIM:
I tried one artificial yellow coloring.
JIM:
On cotton, it initially produced a strong color, but the color disappeared as soon as I rinsed the cloth.
JIM:
I had planned to test it on nylon, too, but I decided not to continue.
TUTOR:
Were you concerned about health risks?
JIM:
I assumed an approved food coloring would be harmless.
TUTOR:
It is usually safe, although a small number of people can have an allergic reaction.
NARRATOR:
Before you hear the rest of the discussion, you have some time to look at questions 25 to 30.
NARRATOR:
Now listen and answer questions 25 to 30.
TUTOR:
Which natural dyes did you investigate?
JIM:
It creates a vivid yellow and is commonly used in foods such as curry.
TUTOR:
It may have health benefits when eaten, but as a fabric dye, it often fades after only a few washes.
JIM:
I also put beetroot dye on wool.
JIM:
Beetroot stains my hands bright red whenever I prepare it, so I expected a similar result.
JIM:
Instead, the wool turned a thin, creamy color.
TUTOR:
Did you read about Tyrian purple?
JIM:
It is obtained from shellfish, and because it was exceptionally rare, only powerful people wore it in ancient times.
TUTOR:
It disappeared from use centuries ago, though a modern researcher recently obtained a little.
TUTOR:
Chemical dyes can now create the same purple.
TUTOR:
What about black dyes?
JIM:
The process was complicated because I had to treat the cloth first, so it would absorb the color.
TUTOR:
I hope you wore gloves.
JIM:
I knew it could be dangerous.
TUTOR:
Swallowing logwood dye can be extremely poisonous.
TUTOR:
Did you consider an insect-based color such as cochineal?
JIM:
I did not make it myself.
JIM:
Crushing insects would have taken too long, and they are not found locally.
JIM:
The prepared dye was easy to order online, but it was extremely expensive.
TUTOR:
It is powerful, which is why cooks use only tiny amounts, and it is rarely chosen for textiles.
JIM:
I also read that iron oxide can color fabric if the metal is allowed to rust while touching it.
TUTOR:
That method works on cotton, but the metal can weaken the cloth, so material treated this way may not last long.
TUTOR:
The shades are also rather subtle, which some people dislike.
TUTOR:
You have clearly done a great deal of work.
NARRATOR:
That is the end of part three.
