The easy way to duller wool – How to penny dye

Written by Cindi Gay

penny dye wool, panny dyeing

If you haven’t tried this yet, you’re in for a treat. This is a great technique for beginners because all you need is a container large enough to hold the wool, several dollars in pennies (don’t be stingy here), water, and non-sudsy ammonia. Add time and you can change the most obnoxious wools into the most desirable. Penny dyeing will make your wool, generally darker and duller.

This process can be done even during record breaking hot temperatures. No stove required.

Nice and Easy hooked rug
Nice and Easy, pattern available from House of Price

Notice the slight mottling in the background of this rug. I wanted to add my granddaughter’s hand print and her name in her second grade handwriting to the background on the left side of the rug. I added my hand print, my name (“Nana Gay” to her), and the year on the right end of the rug. I didn’t want to detract from the rug so I needed the color to be similar to the background. I had dyed the background and planned to return to the dye pot. Thanks to the hot weather in the summer of 2002, I used the penny method instead. It only took about 24 hours for the wool to change enough for me to use. Keep an eye on your wool while it is soaking. Depending on the amount of wool, pennies and ammonia you use your time will be much different. Some changes happen in just a few minutes, others can take many days.

How to penny dye

  1. Fill a container (with a lid) with enough water to cover your wool. I often use one of my dye pots because it’s too hot to do any dyeing on the stove. A student of mine uses a gallon jar. Glass jars can break if they are sealed and left in the sun. Please use caution. I like the glass jars because you can watch the transformation taking place. A large plastic sherbert container works fine, anything that will hold water and ammonia.
  2. Add several dollars of pennies to the bottom of the container. No need to count, just several large handfuls. You can’t add too many. Too few may not work at all or will take longer to work.
  3. Add a few glugs of ammonia. The more water you use, the more ammonia you will need. The chemical reaction will take place faster if you add enough ammonia. If you’re not sure, start slow. You can add more ammonia in a day or so if nothing is happening.
  4. Add the wool. You can add several different wools if you like, but remember that some of the dyes will leak and discolor the others. Sometimes this is exactly what you want. Experiment! If you are using red, be careful. Like a red sock in the white load of laundry, everything will end up with a pink cast.
  5. Add the lid. The ammonia stinks! And wait. If you are trying to change the bountiful recycled red plaid wool, be patient. It make take a week or two. Other wools may change in less than an hour.

Timing is everything

Be sure to keep a small piece of the original rug hooking wool nearby to check the progress. Compare wet to wet. I usually keep the scrap in a small cup of water next to the container. When you want to compare, just remove both without squeezing the water out.

I usually check the first time in about 30 minutes. If nothing noticeable has happened, double the time to 60 minutes before checking again. Check again in 2 hours, 4 hours, 8 hours, etc. Once you start to notice a change begin checking at shorter intervals. You can put the wool back into the ammonia and pennies, but this is a stain and you cannot reverse the process. When in doubt, stop early or process two pieces and take them out at different times. One or the other should work after they are dry.

Remember that wet wool appears darker than dry wool. That is why it is important to compare wet to wet.

Tips and Comments for transforming your rug hooking wool

  1. Use White for instant snow. Penny dyed wool is a great dirty white for snowmen, Santa’s beard, etc. I start with white wool but not natural. Natural has a slight yellow cast that I can ignore except when I am dyeing snow or sky.
  2. Camel: I’ve had some camel colored wool change to a mint green! This process is unpredictable but fun.
  3. Red plaid: If you are patient, really patient, you will get a wonderful, soft cinnamon plaid – wonderful in any piece.
  4. Yarn: Don’t pass up the 100% wool yarn you find at garage sales, etc. The most awful colors can be made useable after spending time with the pennies.
  5. Heat can speed up the process but DO NOT PUT IT ON THE STOVE. They evacuate cities due to ammonia fumes. You can put the pot in a sunny part of the yard if you are not using glass. A sealed glass container could break unexpectedly if it is left in the sun. Be safe. Adding warm water when you add the pennies and ammonia can also jump start the reaction.
dye wool with pennies


This is a photo of my actual penny collection. They are too ugly to spend or take to the bank, but that’s OK because I can use them over and over. They are worth so much more when used as a simple, no heat dye solution to ugly wool colors.

The Dangers

I received this email from Jean O.

On another note, please, please, please emphasize to your students the importance of doing the penny dying outside. There have been cases of deaths from exposure to ammonia and most hospitals don’t know how to deal with an ammonia exposure since it does not present itself like most irritants. The consequences from this chemical are delayed and may not show up for 12 – 24 hours and therefore the person is often home sleeping and not monitored and therefore found dead in the morning. Sorry for my soapbox, but I’ve been in Occupational Health for 38 years and have seen far too many severe injuries or heard of untimely deaths that could have easily been prevent!!

Jean o.

Be careful everyone.

Have you tried the process? How did you use the wool?

Canadian flagNo pennies? No problem. Copper works as well. Get some scrap copper pipe and have it cut into very small, about 1″, pieces and use that instead. Same process. The copper pipe pieces take up a lot more space but you don’t need as much weight so it evens out.

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