Theme: Bringing Art
to Life in Schoolyards
Dyeing to Get Started
Details for Growing Classrooms
Colors from plants have been used throughout history to enhance
people's lives -- for decorating animal skins, fabrics, crafts,
hair and bodies. They've been used to distinguish serf from
master and to serve as banners in war. Your classroom garden,
vacant lot, school grounds, and local grocery store can provide
fuel for investigating the ways in which plants have enriched
and continue to color our world. In doing so, your students
can explore plants up close, design inquiry investigations,
explore chemistry concepts, and have an intriguing lens for
learning about history and other cultures.
ABCs: About the Botany and
Chemistry of Dyeing
Invite your students to muse about why plants have so many different
colors. What purpose might they serve for the plant? Have students
recall what they've observed and already know about plants to
help them consider this question. The green in most leaves is
surely the most ubiquitous plant color. The green pigment chlorophyll
in the leaves helps capture the sun's energy and convert it
to chemical energy, which is then stored and used as food for
the plant. Colors in flowers are adaptations that attract insects
and other animals who, in turn, pollinate and help plants reproduce.
Some plants have colorful fruits that attract animals who eat
them, inadvertently spreading the plant's seeds as they do so.
Scientists believe that other plant pigments may help protect
plants from disease. Despite what we know about the role of
a few of the thousands of plant pigments, the role of most colors
in plants remains a mystery to scientists!
Most plant parts have a mixture of pigments, which is why dyes
made from plants tend to appear more subtle and muted -- less
"pure" -- than synthetic dyes. These "earth tones" in plant
dyes intrigue many hobby and craft dyers, since the rich hues
of mother nature, composed of many colors, all seem to "go together."
Although plants exhibit a wide range of colors, not all of
these pigments can be used as dyes. Some won't dissolve in water,
some will not hang on to fibers, and others will fade when washed
or exposed to air or sunlight. It's not obvious from looking
at plant colors which will reward us with vibrant dyes -- a
fact that can lend shades of mystery and excitement to your
classroom dyeing explorations.
It's generally easier to dye animal fibers like wool and silk
than plant-based fibers like cotton or linen. Consider inviting
your students to observe and compare different types of fibers
or fabrics under magnifiers. The scale-like protein molecules
in wool fibers provide a lot of active "sites" to which pigment
molecules can attach. Cotton, flax, and other plant fibers,
on the other hand, are made mostly of smoother cellulose, which
has few sites available to combine with color molecules.
To help dyes bind better to fibers, dyers typically use different
mordants, most of which are salts of metals like aluminum,
iron, tin, and chrome. The word mordant actually comes from
the latin mordre meaning "to bite," since early dyers thought
these substances enabled the dye to get a better bite on fibers.
Some dyes will bind well without mordants. Most plants will
produce different colors depending on the mordant used. Since
some of the mordants used are toxic, we only recommend one --
alum -- for classroom use. Tannic acid, found in many trees,
can also act as a mordant. This means you can dye wool with
black walnut hulls, which are high in tannic acid without adding
extra mordant. You can also often affect dye colors by changing
the pH of the dye solution, making it more acidic, for example,
with white vinegar.
Dyeing ... To Get Started
Inspired to explore plant dyes with students, but unsure of
where to begin? Investigating plant dyes can be as simple a
project as simmering some onion skins, dipping in yarn, and
observing to see what colors are revealed. Or it can be a more
complicated project involving researching, gathering, and experimenting
with different types of plants, mordants, and dyeing techniques.
It might tie into a study of different cultures (e.g., Navaho)
or periods in history (e.g., Middle Ages). In any case, we hope
it will provide a centerpiece for stimulating student curiosity
and questions, and lead to fruitful inquiries and adventures.
Finding Plant Materials -- Your students can locate
plant materials for dyeing from several sources. They can collect
them in the wild, grow them, or purchase dye plants from a grocery
story or catalog specializing in natural dyes. You'll probably
choose some combination of sources. If you have a classroom
garden, you may unintentionally grow some dye plants,
since you can extract interesting colors from a range of common
garden and roadside weeds.
If you collect plants or plant parts for dyeing, be sure to
use plants that grow in abundance, taking care not to collect
any rare or protected species. You will need a lot of plant
material. A four-to-one ratio of fresh plant material to wool
(by weight) for dyeing is generally recommended, and plant fibers
like cotton require even higher proportions. That is just a
ballpark number, though. We hope you'll encourage your students
to experiment with different proportions of plant materials.
The list below includes just a fraction of the plants others
have used to produce dyes. Exactly what results you will get
depends on a host of factors, including soil type, moisture
content, mordant used (if any), fabric, ripeness or freshness
of the material, how finely you shred it, and proportion of
plant material to fabric. Therein lie the mysteries and opportunities
for your students to question and experiment. Don't let your
students be limited by this list. Encourage them to observe
plants in the environment, make predictions about new plant
dyes, and investigate their theories. Students might want first
to observe and create a list of clothing colors, then brainstorm
natural plant materials they think might produce each color.
Keep this list available throughout your dye project for reference
and to inspire investigations and reflections.
Some Plants to Grow and Collect for Dyeing
- alder leaves (yellow)
- birch leaves (yellow/tan)
- black walnut hulls (black)
- red cabbage (pinkish)
- carrot tops (green)
- coffee grounds (tan)
- elderberries (blue/gray)
- mint leaves (yellow)
- parsley leaves (yellow)
- spinach plants (green)
- tomato plants (pink/blue)
- turmeric (orangish)
- wild grapes (purple)
- wild mustard (yellow)
Garden Flowers
- aster (yellow)
- black-eyed Susans (yellow)
- chamomile (yellow)
- coreopsis (orangish)
- marigolds (yellow)
- sunflowers and seeds (gold)
- zinnias (yellow)
Weeds
- bindweed (yellow)
- cocklebur (brass)
- dandelions (magenta) (with no mordant)
- dock (brass)
- giant ragweed (brass/gold)
- goldenrod (brass)
- mullein (yellow)
- redroot pigweed (brass/gold)
Getting the Color Out-- Once your students have harvested
plant parts and predicted which colors might emerge from which
plants, consider having them brainstorm how they think they
could "extract" the colors from the plants. Record their thoughts
so they can set up investigations to test some of their ideas.
Here's one method: Shred plant materials to expose more surface
area from which color can be extracted. Cover the plant materials
with water in an enamel pot, simmer them for about an hour until
the water is colored and the plant tissues look bleached, then
strain the dye bath through cheesecloth or an old stocking to
get rid of plant material. (Some dyers do simultaneous dyeing
in which the plant materials are left in when the fabric is
dyed. If you decide to do this, place the plants or the fabric
in an old stocking or net bag to protect the material from direct
contact.)
Treating the Material-- First, wash your fabric or yarn
with soap to remove dirt and oils that could interfere with
the dye binding to the fabric. If you're using a skein of yarn,
tie it loosely so the mordant and dye can penetrate well. If
you're just getting started and want to do some simple dyeing
explorations, you may choose not to use a mordant to "fix" the
dye. Some plants will yield colorfast dyes without a mordant
(e.g., tumeric and black walnut hulls), and others may yield
color without a mordant, but it may wear out with washing and
sunlight (e.g., purple cabbage).
If you're using the mordant alum to help the dye bind better
to the fabric, you can either pretreat the yarn or fabric (as
is typically done) or try adding the mordant directly to the
dye bath. You can usually find alum (make sure to get aluminum
potassium sulfate) at a pharmacy or craft supply store and cream
of tartar from a grocery store. To pretreat the yarn or fabric,
measure 3/4 tsp. alum plus 1/4 tsp. cream of tartar per each
quart of water in your dye bath. Dissolve this in a cup of hot
water, then add it to a pot of water (one quart of water per
each ounce of fabric). Wet the fabric to ensure penetration,
then add it to the mordant solution. Heat slowly at a simmer
for one hour. (Wool, in particular, doesn't respond well to
rapid temperature changes.) Remove the pot from the heat, then
cool and rinse the fabric before adding it to the dye bath.
Once you add fabric or yarn to the dye bath, simmer it for
30 minutes to an hour, turning the material gently. Stir and
check the color every 10 minutes or so. Students may want to
experiment by leaving the fabric in for different amounts of
time, even allowing it to cool and steep in the dye bath overnight.
Or they might want to do some "tie dyeing" to see what patterns
emerge when they tie knots, rubber bands, or otherwise prevent
the dye from penetrating throughout the fabric. Rinse dyed materials
with progressively cooler water and hang them to dry.
Plant Colors Throughout History-- Since prehistoric
times, humans from across the globe have used plant pigments
to enrich their lives. Historians and scientists believe that
prehistoric animal skins and cave paintings dating back to 15,000
B.C. were dyed with plant pigments. They've discovered examples
of early dyed fibers in Egypt dating to around 2000 B.C., and
Chinese records revealing even earlier use of plants as fabric
dyes. Ancient Britons, called Picts, used woad, a plant, to
dye their bodies blue and frighten enemies in battle, while
the British marched against the Americans in their well-known
red coats dyed with madder root. Ask your students to imagine
and discuss how they think early humans might have discovered
that they could use plant pigments to color their bodies, hair,
crafts, animal skins, and fabrics.
Natural colors have also played important roles as cultural
symbols, often being associated with status, class, and religion.
The less common reds and purples, for instance, were at times
reserved for royalty, while more common dye colors were relegated
to the "common" folk.
By the Middle Ages, dyeing had become an important industry
in Europe. Farmers specialized in growing specific dye plants,
and well-organized dyers guilds carefully guarded their craft
secrets. Meanwhile, throughout the world, indigenous people
were using native plant dyes for clothing, cosmetics, and crafts.
In the 1800s a scientist named Sir Henry Perkin was trying
to synthesize quinine to treat malaria but, as often happens
in science, made an entirely different discovery. He inadvertently
produced the first synthetic lavender dye, which he called mauve.
Mauve soon became the popular fashion color of the era.
This discovery spelled the beginning of the end of the natural
dye industry, and by the mid- to late 1800s, less expensive,
more predictable synthetic dyes had replaced natural dyes. In
this country today, natural dyeing is done primarily as a craft,
often by those who knit and weave. Increasingly, however, people
concerned about the pollutants produced by the synthetic dyeing
process used in the textile industry are promoting undyed or
naturally dyed products.
Egg-citing Colors
Using plant dyes to decorate eggs requires minimal materials
and can spark explorations of different dye plants, concentrations,
and dyeing methods. A basic method for dyeing eggs is to bring
two cups of water to a boil, add plant materials plus one tablespoon
of vinegar and simmer for at least ten minutes. Strain out the
plant materials, then dip in and simmer eggs for at least ten
minutes. If students use wax to draw designs on the eggs, the
wax will resist the dye, and patterns will emerge. Some teachers
report students creating intriguing patterns by wrapping and
securing plant materials (e.g., cabbage leaves) around eggs
before simmering them.
Author: Eve Pranis
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