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How to Dye Flour Sack Towels in 3 Steps
by:
Mary's Kitchen Towels Team
|
Updated April 2026
In This Guide
Dyeing fabric is a simple process once you understand the two things that go wrong most often: inadequate preparation and the wrong mordant for the fiber type. Flour sack towels are 100% cotton — a cellulose-based plant fiber that is notoriously resistant to dye when untreated, but produces rich, lasting color when prepared correctly.
This guide walks through all three steps — scouring, mordanting, and the dye bath — for unbleached flour sack towels, which take dye more evenly than bleached white cotton. Follow the steps in order and the results are reliable and repeatable.
Before You Start — Cotton and Dye
Cotton and other cellulose-based plant fibers are not naturally porous at a microscopic level. Unlike wool or silk — animal (protein) fibers that bond readily with most dyes — cotton resists dye absorption and loses color quickly without proper preparation. Understanding this is the key to getting good results.
Two factors determine how well your dye job turns out: how thoroughly you scour the fabric, and which mordant you use. Skip either step and you'll get uneven color, poor saturation, and dye that washes out quickly.
Best fabric for dyeing: unbleached natural flour sack towels
Unbleached natural cotton takes dye more evenly than bleached white cotton, because the bleaching process can affect fiber absorption. Vintage or heavily pre-washed fabric also dyes better than brand new — repeated washing removes more manufacturing residue, allowing dye to penetrate more directly. Our unbleached flour sack towels are the best starting point for this process.
Tannin-rich dyes: If you're using natural dyes, choose ones rich in tannins — oak gall, black tea, pomegranate rind, or walnut hull. Tannins attach strongly to plant-based fibers and can sometimes eliminate the need for a mordant entirely. They also produce deeper, more saturated color on cotton than low-tannin natural dyes.
Step 1: Scour Your Fabric
Step 1 of 3
Scouring — Remove Everything That Blocks Dye
Scouring removes the oils, waxes, dirt, and manufacturing residue that prevent dye from bonding evenly with cotton fibers. Cotton flour sack fabric can carry up to 35 grams of wax and processing residue per towel — invisible to the eye but highly effective at blocking dye uptake. Scouring is not optional.
Use soda ash for scouring cotton — not regular washing powder. Soda ash is significantly more aggressive at breaking down wax and fat molecules on cotton fiber. Regular washing powder is too mild to achieve the same result.
Scouring process:
- Machine wash the flour sack towel first on a long, hot cycle with no fabric softener and no bleach.
- Fill a stainless steel pot with approximately 5 liters of water and bring to a boil.
- Weigh out approximately 35 grams of soda ash. Do not add water to the soda ash — add it directly and carefully to the boiling pot. It will bubble briefly.
- Once the bubbles clear, add the still-wet flour sack towel to the pot.
- Stir with a long wooden or stainless steel spoon. Reduce to a hard simmer and cook for up to two hours, half covered.
- Stir every 15 minutes to ensure even scouring across the fabric.
- After two hours, remove from heat and allow to cool before removing the towel. The water will likely be brown or grey — this is the residue you've removed. If the water is very dark, repeat with fresh water and soda ash until it runs mostly clear.
- Rinse the scoured fabric thoroughly before proceeding to mordanting.
Step 2: Mordant the Material
Step 2 of 3
Mordanting — Prepare the Fiber to Hold Color
A mordant is a substance that bonds to fabric fiber and creates attachment points for dye molecules — without it, most dye simply washes out of cotton after a few cycles. The type of mordant matters: animal fibers use aluminum potassium sulfate, but plant-based fibers like cotton require aluminum acetate for best results.
After mordanting with aluminum acetate, follow up with a wheat bran bath. The wheat bran helps fix the aluminum acetate into the cotton fiber more thoroughly, maximizing the dye's eventual uptake. Think of it as the final preparation before color.
Mordanting process:
- Soak the scoured flour sack towel in warm water for a minimum of two hours.
- Fill the pot halfway with regular tap water — no need to heat it this time.
- Dissolve the aluminum acetate in a small container of hot water, then add the solution to the pot and stir well.
- Wearing gloves, add the wet towel to the pot. Gently squeeze the fabric while it soaks to help the mordant penetrate the weave.
- Leave overnight. Some mordants require up to four days, but an overnight soak is generally effective for cotton flour sack fabric.
- When ready, rinse the fabric thoroughly to remove any unattached mordant before proceeding to the dye bath.
The wheat bran bath
After the aluminum acetate soak and rinse, a wheat bran bath further fixes the mordant into the cotton fiber. Simmer a handful of wheat bran in water for 20 minutes, strain, and soak your fabric in the warm bran water for an hour before dyeing. This step is optional but produces noticeably more saturated, longer-lasting color — particularly with natural dyes.
Step 3: Prepare Your Dye Bath
Step 3 of 3
The Dye Bath — Apply Color
The dye bath is where the most variation and artistic expression happens. The quantity of dye relative to water determines saturation — more water dilutes color, less water concentrates it. Start with the dye manufacturer's recommended ratio and adjust from there based on your results.
Dye bath process:
- Mix your dye into a large container or pot — large enough to hold the flour sack towel with room to move freely. Cramped fabric dyes unevenly.
- Add your mordanted, wet towel to the dye bath. The fabric should be wet when it enters the bath — dry fabric creates uneven dye uptake at the entry point.
- Stir continuously for the first 15 minutes to prevent uneven color patches forming where fabric touches itself.
- After the initial stirring, continue to agitate regularly — every 10–15 minutes — for the duration of the dye bath.
- After approximately two hours, remove the fabric. Rinse thoroughly in progressively cooler water until the water runs clear.
- Wash gently with mild detergent, then hang to dry away from direct sunlight, which can fade freshly dyed cotton.
One important advantage of cotton dyed using this process: once scoured and mordanted, you can re-dye the same fabric multiple times without repeating the preparation steps. Layering colors in sequence — yellow first, then blue over it to produce green, for example — produces complex results that single-bath dyeing cannot achieve. Experiment with this freely; the mordanted cotton is ready to accept dye again as soon as it's rinsed and wet.
Shibori Indigo Dyeing
Shibori is a Japanese resist-dyeing technique that creates geometric patterns by folding, binding, or compressing the fabric before immersion in indigo dye. The resist areas — wherever the fabric is tightly bound — stay undyed, producing the characteristic white-on-indigo pattern. The results look complex but the process is straightforward, and indigo dye kits (such as the Jacquard Indigo Dye Kit) include almost everything needed.
Flour sack cotton is an ideal substrate for shibori — the tight 100% cotton plain weave takes indigo cleanly and produces crisp resist lines. The polyester hem thread will not take indigo and will remain white, which tends to complement rather than clash with shibori patterns.
Five shibori techniques for flour sack towels
Technique 1
Square Resist (Itajime)
Accordion-fold the towel lengthwise, then accordion-fold again crosswise until you have a compact square. Clamp a wooden square resist on each side and bind tightly with rubber bands. The clamped areas resist the dye and emerge as a geometric white pattern. Most indigo kits include wooden square resists for this method.
Result: Clean geometric squares in a repeating grid pattern.
Technique 2
Clothespin Resist
Accordion-fold the towel lengthwise, then fold in half longways once. Clip wooden clothespins evenly along both sides of the folded fabric — the clothespins act as the resist, blocking dye wherever they clamp. The tighter and more evenly spaced the clothespins, the more defined the pattern.
Result: Stripe-like resist marks with soft edges where the dye bleeds slightly around the clips.
Technique 3
Twine Binding
Accordion-fold lengthwise, then accordion-fold again into a square. Tightly wrap and tie twine around each side of the folded square. More dye bleeds through the twine lines than with wooden resists, producing a softer, more organic result than the square resist method.
Result: Softer geometric pattern with more indigo bleeding into the resist areas — more organic feeling than itajime.
Technique 4
Popsicle Stick Clamp
Accordion-fold the towel lengthwise, then fold in half once. Place popsicle sticks on both the top and bottom of the folded rectangle and bind the ends of the sticks together with rubber bands. This method works best with a half yard of fabric — a full yard may not allow the dye to penetrate all the way through, though the partial penetration creates an interesting gradient effect.
Result: Linear resist pattern with a gradient where dye didn't fully penetrate. Subtle and distinctive.
Technique 5
Pinch and Bind (Arashi variation)
Lay the towel flat and pinch small sections of fabric, tying each pinch off tightly with a rubber band. You can work in an organized grid pattern or randomly across the surface — both produce interesting results. The rubber-banded pinches resist the dye and appear as small circular white bursts in the finished piece.
Result: Scattered circular or spotted resist pattern. Random binding produces a highly organic, unique result on every towel.
Shibori dyeing tips
Immerse the bound fabric in the indigo vat and agitate gently for 1–3 minutes. Remove and allow to oxidize in open air for 10–15 minutes — the fabric will shift from yellow-green to blue as it oxidizes. For deeper color, repeat the immersion and oxidation cycle 2–3 times before rinsing. Once rinsed, remove all resists and unfold carefully to reveal the pattern. Wash before using to remove any unfixed dye.
Flower Hammering — Natural Dye Printing
Flower hammering (also called botanical printing or eco-printing) transfers the natural pigment from fresh flower petals directly into cotton fabric using mechanical pressure rather than a dye bath. The technique is simple, requires no heating or chemicals, and produces one-of-a-kind designs that can't be precisely replicated — the natural variation in each flower means every towel is unique.
Important note on longevity: Flower-hammered color is a natural pigment, not a permanent dye. The color will fade with washing and sunlight exposure faster than chemical or fiber-reactive dyes. These towels are best used as decorative pieces or gifts rather than everyday kitchen workhorses. Heat-setting with a dry iron immediately after hammering helps extend the color life.
How to hammer-dye a flour sack towel with flowers
- Choose your flowers — bright colors transfer best. Reds, purples, dark pinks, and blues produce the strongest color transfer. Good choices include carnation petals, violets, heather, petunias, and alstroemeria. Avoid pale or white flowers — they transfer very little pigment. Large petals like roses tend to look like stains; small flowers and individual petals produce more delicate, interesting results.
- Plan your design — sketch a rough layout before starting. Accented corners are the most popular format for tea towels — four corner arrangements of 3–5 flowers each. Working across the whole surface is also possible but more labor intensive.
- Tape the flowers in place — lay the towel face-up on a thick piece of wood (a 2×4 works well). Tape each flower or petal face-down onto the towel surface using painter's tape, in the position and orientation you want.
- Hammer the petals — hit each petal firmly and evenly with a hammer, working across the entire surface of the petal to transfer all the pigment. You'll see color coming through the towel immediately. Hit harder than you think you need to — the first attempt almost always requires more force than expected.
- Remove and repeat — carefully peel off the tape and spent flower. The remains will be flat and dry. Repeat with additional flowers until you've completed your design. Green leaves also transfer and can be used for stems or fill.
- Heat-set immediately — press the finished towel with a dry iron on the highest cotton setting. No steam. This is the most important step for color longevity.
Hibiscus Natural Dye Bath
Dried hibiscus flowers produce a vivid pink-to-magenta natural dye on cotton — one of the most accessible and reliably colorful natural dyeing options available. Dried hibiscus is sold as loose-leaf tea in most natural food stores, making the materials easy to source without specialist suppliers.
Natural flower dyes like hibiscus require a mordant to bond with cotton. For a quick natural dye project, white vinegar works as an accessible mordant substitute — while not as permanent as aluminum acetate, it's sufficient for decorative projects and significantly simpler to work with.
Hibiscus natural dye process
- Pre-mordant the fabric — combine 1 part white vinegar with 4 parts water in a large pot (example: 2 cups vinegar + 8 cups water). Bring to a simmer and add your flour sack towels. Simmer for one hour, then let cool and rinse the fabric before dyeing.
- Prepare the dye bath — in a separate pot, add approximately 1.5 cups of dried hibiscus flowers to 10 cups of water. Bring to a boil for 30 minutes, then reduce to a low simmer. The water will turn a deep crimson-purple.
- Dye the fabric — add the rinsed, wet towels to the hibiscus dye bath. Keep them submerged and stir regularly. Leave for 20–40 minutes depending on how deep a color you want. Note that the color will be noticeably lighter once the fabric dries.
- Rinse and dry — remove the towels and rinse under cool water until the water runs clear. Hang to dry away from direct sunlight.
- Wash before use — wash gently before first use to remove any unfixed dye.
Other natural dye options for cotton
Turmeric — produces a vivid yellow. Works with a vinegar mordant and is easy to source. Color fades faster than other natural dyes when exposed to sunlight. Black tea — produces a warm tan or beige. Particularly useful for aging or antiquing white cotton. Onion skins — yellow-gold with an alum mordant, deeper orange with an iron mordant. One of the most colorfast natural dyes available for cotton. Avocado pits and skins — produces a surprisingly vivid pink-to-rust on unmordanted cotton. Particularly effective on pre-washed fabric.
Tips for Dyeing Flour Sack Towels
- Cotton thread vs polyester thread: The fabric is 100% cotton and dyes well. The hem stitching is polyester, which does not accept fiber-reactive or natural dyes. The hem lines will remain their original color — white or off-white — while the cotton fabric around them changes color. This is a characteristic of the construction, not a defect. Many crafters plan their designs to incorporate the hem as a border element.
- Unbleached natural towels dye more evenly than bleached white ones. The bleaching process can affect fiber absorption and sometimes produces uneven uptake. Our unbleached flour sack towels are the recommended choice for any dyeing project.
- Pre-wash before dyeing — even pre-washed towels benefit from a hot wash before dyeing to open the fibers fully.
- Wet fabric before immersion — always add wet fabric to the dye bath. Dry fabric creates uneven uptake at the point of entry.
- Stir continuously for the first 15 minutes to prevent color patches where the fabric touches itself.
- Depth of color — more dye relative to water produces deeper color. More water dilutes color. Start with the manufacturer's recommended ratio and adjust based on your results.
- Re-dyeing is easy — once mordanted, you can re-dye the same towel multiple times with different colors to produce layered, complex results.
Unbleached Flour Sack Towels for Dyeing
Natural unbleached 100% cotton — the best starting point for fabric dyeing. No minimum order. Pre-washed. Ships in 1 business day.
Frequently Asked Questions
Can you dye flour sack towels?
Yes — flour sack towels are 100% cotton and dye well when properly prepared. Cotton requires scouring to remove manufacturing wax, and mordanting with aluminum acetate to bond dye permanently to the fiber. Unbleached natural towels take dye more evenly than bleached white ones.
What type of dye works best on flour sack towels?
Fiber-reactive dyes (like Procion MX) produce the most vibrant, colorfast results on 100% cotton. Natural dyes rich in tannins also work well and can sometimes self-mordant on plant fibers. All-purpose dyes work but produce less saturated, less permanent color on cotton compared to fiber-reactive options.
What is scouring and why is it necessary?
Scouring pre-washes fabric in boiling water with soda ash to remove oils, wax, dirt, and manufacturing residue that block dye from bonding with cotton fibers. Cotton can carry up to 35 grams of wax per towel from manufacturing — invisible but highly effective at preventing even dye uptake. Scouring is not optional for good results.
What is a mordant and do you need one for cotton?
A mordant helps bond dye permanently to fabric fiber. For cotton, aluminum acetate is the correct mordant — it bonds to plant-based (cellulose) fibers. Without a mordant, most dye washes out of cotton quickly. Follow with a wheat bran bath after the aluminum acetate soak for maximum color retention.
Should I use bleached or unbleached towels for dyeing?
Unbleached natural flour sack towels dye more evenly. The bleaching process can affect how cotton fibers absorb dye, sometimes resulting in patchy color. Vintage or pre-washed fabric also dyes better than brand new, as repeated washing removes more manufacturing residue.
Can you dye flour sack towels more than once?
Yes — after scouring and mordanting once, you can dye and re-dye as many times as you want. Layering different colors in sequence produces complex results. Apply lighter colors first and darker colors over the top for the most controlled outcomes.
Will the hem stitching dye the same color as the fabric?
No — the fabric is 100% cotton and takes dye well, but the hem stitching is polyester. Polyester does not accept fiber-reactive or natural dyes the way cotton does — the hem lines remain their original color (typically white or off-white) while the cotton fabric around them changes color. This is a characteristic of the construction, not a defect. Many crafters incorporate the lighter hem lines as a border feature in their designs.
What is shibori dyeing and can you do it on flour sack towels?
Shibori is a Japanese resist-dyeing technique that creates geometric patterns by folding, binding, or compressing the fabric before indigo dye immersion. The bound areas resist the dye and emerge as white patterns against the indigo background. Flour sack cotton is an excellent substrate for shibori — the tight plain weave takes indigo cleanly and produces crisp resist lines. Common techniques include square resist (itajime), clothespin resist, twine binding, popsicle stick clamping, and pinch-and-bind.
Can you dye flour sack towels with natural dyes like hibiscus or turmeric?
Yes — hibiscus produces vivid pink-to-magenta, turmeric produces yellow, onion skins produce gold to orange, and black tea produces warm tan. Natural dyes require a mordant to bond with cotton — aluminum acetate is the most effective, but white vinegar works as a simpler alternative for decorative projects. Natural dyes fade faster than fiber-reactive dyes, particularly with sunlight exposure, so natural-dyed towels are best used as decorative pieces rather than everyday kitchen workhorses.
What is flower hammering and how does it work on tea towels?
Flower hammering (botanical printing) transfers natural pigment from fresh flower petals directly into cotton fabric by taping the petals face-down and hammering them firmly. Bright-colored flowers — carnations, violets, petunias, alstroemeria — work best. Heat-set immediately after with a dry iron on the highest cotton setting. The color will fade with washing, so flower-hammered towels are best as decorative pieces or gifts rather than daily-use kitchen towels.
Written by
Mary's Kitchen Towels Team
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