How to Scour

Our How To guides are intended to make the dye process easy for our customers, from mordanting and scouring your fibers to dyeing with an assortment of dyes. You can find other How To guides here.

WHAT IS SCOURING?

“Scouring” is the textile term for washing or cleaning fibers prior to mordanting and dyeing, often using near boiling water. If the fiber is not clean, the mordant and dyes will not adhere well to the fiber. Fiber needs scouring if it feels greasy, stiff, sticky, tacky, smells or is visibly dirty. Products that are sold as Ready for Dyeing or Prepared for Dyeing (RFD or PFD) often need a light scour prior to use. Products sold as gray goods, greige or are in their raw state require a thorough scour. An easy way to tell if your fibers need scouring is to observe the scour water as you bring up the heat. If the water looks like weak tea (or strong tea, for that matter), then scouring is required.

The scouring methods for protein and cellulose fibers are different. If you are dyeing cellulose fibers, please scroll further down to the Scouring Cellulose Fibers section.  Scouring information for silk fibers is also noted below.

SCOURING WOOL

We scour protein fibers with Orvus paste. It was first used as an equine and livestock soap, but quilters and other fiber artists use it as a mild pH neutral soap for textiles. When scouring, note that all fibers should be pre-wet with tap water so absorption is even.

CALCULATING THE AMOUNT OF SCOUR

Orvus Paste: the amount of Orvus paste should be 1% of the weight of fiber.

“Weight of fiber” refers to the dry weight of the yarn or fabric to be scoured, allowing you to quickly and easily calculate how much to measure. A kitchen scale is handy to determine the weight of yarns or fabrics.

WHAT YOU WILL NEED

This list of ingredients is for 100 grams/4 ounces of fiber, and with 1% Orvus paste to scour. Adjust the amount of materials as necessary, per the percentage guidelines above.

  • 100 grams/4 ounces fiber
  • 1 gram/.04 ounces/1/4 teaspoon Orvus paste (if fibers are heavily soiled, like raw wool in the grease, use up to 1 teaspoon of Orvus paste)
  • A container for dissolving Orvus paste
  • A large stainless steel dye pot, large enough to hold your fibers with plenty of room to move around
  • Heat source

Instructions:

Measure the Orvus paste and place it into a container that you can pour hot water into. Bring about a cup of water to a boil, and pour it into the container to dissolve the Orvus paste.

Fill a dye pot with room temperature water and place on a heating source, then add the dissolved Orvus paste to the dye pot. Stir well.

Add the fiber to the dye pot and slowly bring the temperature to 180°F, rotating the fibers gently, being careful not to tangle or felt. Hold at 180°F for 30 minutes.

Remove fibers from the dye pot (be careful as it is very hot), rinse in the same temperature water. You may allow the fibers to cool slightly for safe handling, and you may need to rinse fibers twice. Handle gently to avoid felting and tangling.

Extract excess water and proceed to mordanting. You may also store scoured fabrics dry and protected from dirt and stains until you are ready to mordant.

SCOURING CELLULOSE FIBERS

Scouring is different than washing fabrics, and if you are scouring, you do not need to pre-wash the fibers.  All fibers should be pre-wet so absorption is even.

CALCULATING THE AMOUNT OF SCOUR

Cellulose scour liquid: the recommended amount of cellulose scour liquid is 5.5% of the weight of fiber, or 1 teaspoon for 100 grams of fiber.

Soda ash: the recommended amount of soda ash is 2% of the weight of fiber, or 1/2 teaspoon for 100 grams of fiber.

WHAT YOU WILL NEED:

This list of ingredients is for 100 grams/4 ounces of fiber. Adjust the amount of materials as necessary, per the percentage guidelines above.

  • 100 grams/4 ounces fiber
  • 5.5 grams/.2 ounces/1 teaspoon cellulose scour
  • 2 grams/.3 ounces/1/2 teaspoon soda ash
  • A container to dissolve the soda ash
  • A large stainless steel dye pot, large enough to hold your fibers with plenty of room to move around
  • Heat source

Instructions:

Wet out the soda ash first with a little cold water, and then gradually add boiling water to dissolve.

Fill a dye pot with enough room temperature water so the fibers move easily and place on a heating source. Add the cellulose scour and dissolved soda ash to the dye pot. Stir well.
Add the wet fiber to the dye pot and slowly bring the temperature to 140°F, rotating the fibers gently.

Hold at 140°F for 30 minutes.

Remove fibers from the dye pot (be careful as it is very hot), rinse in cool water, extract excess water and proceed to mordanting.

SCOURING SILK FIBERS

Silk yarn and yardage is generally sold already well scoured; if it is very soft and white, then the sticky protein called sericin has already been removed.  However, if you are working with silk noil, raw tussah yardage or silk yarns that feel stiff, then scouring them will help improve color yield and quality in the dyed goods.

CALCULATING THE AMOUNTS

Soda Ash:  Use 2% or 1/2 teaspoon of soda ash per 100 grams of fiber.

Vinegar:  Use 5% or 1 teaspoon of white vinegar to neutralize the fibers after scouring.

WHAT YOU WILL NEED

  • 100 grams of silk fiber
  • 1/2 teaspoon of soda ash
  • A container to dissolve the soda ash
  • A large stainless steel dye pot, large enough to hold your fibers with plenty of room to move around 
  • A large stainless spoon or tongs
  • Heat source

Wet out the soda ash first with a little cold water, and then gradually add boiling water to dissolve.

Fill a dye pot with enough room temperature water so the fibers move easily and place on a heating source. Add the wet fiber to the dye pot and slowly bring the temperature to 160°F, rotating the fibers gently.

Hold at 160°F for 30 minutes.

Remove fibers from the dye pot (be careful as it is very hot), rinse in cool water, extract excess water and proceed to mordanting.  If the scour water is very dark colored, you may need to scour a second time to remove all of the impurities from the fibers.  Repeat the steps, above.

At the final rinse, add 1 teaspoon of white (distilled) vinegar to the rinse water and let the fiber soak in the vinegar water for 20 minutes.  Remove, rinse in cool water, and proceed to mordanting.