During last week I have over-dyed a silk garment for a client. I am always very hesitant when asked about such an activity as it is mostly unsuccessful. First, the type of fabric needs to be determined (I will only dye cellulose fibres and silk). Second, the stitching thread, zip and of course buttonholes (if any) will remain the original colour. Third, any tight tucks, gathers and folds will act as a resist preventing even distribution of dye colour. And finally, it is common belief that over-dyeing will disguise any fading. Unfortunately this is not the case, the over-dyeing will spread evenly across the previous colour, and the fading will still be evident.
Despite all the above, I decided to give it a go. This garment had been hung amongst others on a rack of clothing, and the narrow shoulders and sides, which had been exposed to the light, had faded. It also had metal and glass bead decorations but because they were stitched, not pasted, I felt they should be okay.
The garment before dyeing. Not easy to see the fading but it is there.
After over-dyeing. The new colour I felt was much more appealing, and the fading was almost eliminated unless you knew where to look.
However, the silk georgette overlay on the skirt took a sad and shrunk, about 10cm/4"! The bodice overlay did not seem to shrink at all. Fortunately the lining dyed the same colour, and both my client and myself felt this shortening of the overlay made a feature, and is actually quite elegant. The beading came through the dye bath well and appeared a lot more refreshed and sparkly.
I have now added shrinkage to my list of reasons why not to over-dye a garment!