July 3, 2013

hand dye process - overview and process variations

All of the colored cord used in WhatKnotshop products is made using a small batch dye process. The term "hand dyed" refers to this process  Here's a discussion of what this means including definition of some of the variables that affect the outcome.

pastel palette here

Cord Materials
The cord materials come in two different basic structures:  One is a twisted cotton cord that looks and feels like a miniature piece of rope. The other is a smooth braided cotton cord with a soft fiber core that looks more like a piece of spaghetti with no surface texture. These two base materials respond to the dye in slightly different ways.

A hank of twisted cotton cord read for the dye bath.
Dye Process overview:
The dye process begins with a color recipe that is based on the dye manufacturers specifications. I use RIT dyes both dry powder packets and liquid from the bottles. The liquid RIT colors can be blended to produce a wide range of color outcomes as can be seen in the Color RIT Formula Guide. I use a standard dye bath mix proportions to prepare the single colors made with the dry dye packs.

Liquid RIT dye and recipe card.

Dye Process Details and Variations:

Cord color:
This is the original native color of the cord material. It can range from grey to white in a variety of shades. The final color outcome is influenced by the amount of grey in the cord. A low concentration dye bath combined with a grey toned cord produces attractive pastel colors. A high concentration dye bath combined with a bright white cord produces brighter more saturated colors.

Dye bath concentration:
This is the amount of dye pigment and the proportion of added water. The less pigment the lower the concentration. A high concentration dye bath is required for good saturation of color especially when using the darker colors like navy and black.

Dye bath temperature:
This is boiling (100 C/ 212 F). A dye bath is brought to a full boil before introducing the cord.

Cord density:
This is a subjective estimate of the tightness of the cord lay. High density or tightly woven cord requires more time in the bath to fully absorb the dye due to the compression of the fibers.  Low density or looser lay cord enables greater dye penetration and absorption in a shorter period of time.

Dye solution penetrates from the outside of the cord towards the center creating a gradient of color in the cord fibers.

Time in bath:
This is how long the cord is immersed in the dye bath. Generally the longer the immersion the more saturated the color due to increased penetration. High density tightly wound cord requires more time in he dye bath to overcome the slow absorption rate.

Batch of cord in the dye bath using the stovetop method

Rinse out process:
Dyed cord is pulled from the dye bath allowed to cool then rinsed out three times in warm water to remove excess dye. Additional rinse cycles are required for high saturation colors like navy blue and black. The purpose of the rinse is to remove excess pigment so it doesn't "run" or bleed out of the finished product. 

1 comment:

Obat Herbal Jantung Koroner said...

NIce for our inormation ! ^___^