Introduction

My intention was to dye needlepoint wool in order to match a piece of fabric.  Often when turning needlepoint into a pillow, a contrasting piece of fabric is chosen for the background because it is difficult to match the color of the fabric to the color of wool used in the background in the piece of art work.  Thus, I would like to dye the wool that will be used as the background of the piece of art work to perfectly match the background fabric in order to create a greater focus on the art work instead of drawing attention away with contrasting colors.

Background

Acid dyes, here Pro Chemical Dyes, must be used to dye protien fibers such as wool. They are called acid dyes not because they are acidic, but because acid, here acetic acid (vinegar), is used in the dyeing process. ( Burch)

The L*a*b* system is a "method for measuring and ordering object color" (Datacolor).

L* numbers measure the lightness.
a* numbers measure red and green. + on the a* coordinate means red - on the a* coordinate means green.
b* numbers measure yellow and blue. + on the b* coordinate means yellow - on the b* coordinate means blue.

I will be using the L*a*b* system coordinates to collect data on my dyed results. Here is a link to reproduce the L*a*b* results.

Supplies

RO Water
Acetic Acid
Sodium Chloride Solution
Pro Chemical Dyes:
            Brilliant Violet
            Navy
            National Blue
            Bright Red
White Needlepoint Wool
Needlepoint Canvas
Needlepoint Needle
A Hot Plate
Pasture Pipettes
Beakers
Stirring Rods
Boiling Stones
Watch Glasses
Thermometer
Paper Towels

Constants

Type of Needlepoint Wool
Amount of Needlepoint Wool used in each test
Technique of Acid Dyeing
Length of Time Dyeing
Style of Needlepointing (basket weaving)

Variable

Dye Recipe

Procedure

First, in making the chemical dyes used in the experiment.  Combine 4.5 grams of dye powder with 250 ml of RO Water.  The Bright Red dye was prepared in this manner.  Because of hard clumps of matter found in the Brilliant Violet dye, Brilliant Violet, Navy, and National Blue were all heated to boiling to help the dye disburse in the water.

The wool was left to soak in RO Water before dyeing for at least 30 minutes.  Sometimes it was left to soak overnight.  The important factor is that the wool is saturated.

Dyeing Procedure

Heat 180 ml of RO Water to at least 40 degrees Celsius in a beaker on the hot plate.  Once at this temperature, add 6 ml of Acetic Acid and 6 ml of Sodium Chloride Solution and 3 ml of dye.  Stir.  Add 5 strands of wool (weighing approximately 3 grams).  Stir occasionally and raise the heat to boiling for one hour.  After one hour, carefully remove the beaker from the hot plate, pour off the dye that did not saturate.  Rinse the wool with cool water and leave on paper towels to dry.

Once dry, needlepoint one strand into a 15 stitch square to be used to measure L*a*b* values with the Colorimeter with basket weaving technique.

This is the dye samples 1-4 from April 18, 2007

Observations and Data

Based on the results of the first 5 samples (really 2-4 since 1 is yellow to be used in the artwork of the needlepoint), I created the recipes for samples 6-9 in hopes of finding the best possible dye recipe to match the fabric sample.

Dye Recipes and Observations:

These are dye samples 6-9 from April 24, 2007.

L*a*b* Results from Colorimeter

Here I am taking the L*a*b* coordinates with the Colorimeter.

Conclusions

Based on these results, the best recipe to dye wool to match the fabric sample would be a combination of #7 and #9.  So, for the final batch of wool, to be used to needlepoint the final project, the following amounts of supplies were used:

40 Strands of needlepoint wool
1440 ml of RO Water
48 ml of Sodium Chloride Solution
48 ml of Acetic Acid
24 ml of dye:  21 ml of Brilliant Violet and 3 ml of Navy

This is the final batch of wool.

Deviations

The biggest deviation is that because of time constrains, I was not able to continue creating potential recipes to find the best one.  I chose to mix the two best recipes in hopes that they would create a happy medium.  Also, while this was not a part of my original experiment, I would have liked to look into Munsell color data as well as the L*a*b* data to be able to compare more data about the color samples.

Links

Burch, Paula E., Ph.D. http://www.pburch.net/dyeing/aciddyes.shtml. Copyrighted 1998-2007 Created: May 2003. Last Updated: 1 January 2007.

Datacolor. http://www.datacolor.com/index.php?name=Sections&req=viewarticle&artid=285. Copyrighted 2002-2006.

Other References

Bordley, John L, Jr.  and Carolyn E. Fitz.  “Pigments/Dyes Lab 2.”  Laboratory Manual:  Chemistry and Art: Chemistry 108.  Sewanee:  The University of the South, Easter Semester 2007.  pp.1-2.

Acknowledgements

Professor Bordley

Professor Fitz