I worked in an art and craft supplies shop for ten years and often had to explain to customers how to dye clothes using this and similar products. After trying it out myself for the first time recently, I found it works just as well as I thought it did.
There are several potential pitfalls. Reading the manual is the key, but it doesn't cover all eventualities or might not be too obvious on some points. Some additional information and contenders for errors that I encountered through my ten years of selling this product are as follows:
1) Using salt substitute instead of the real thing. Yes, this might seem obvious to most, but not to all. What is needed is pure cooking salt (100% NaCl - Sodium Chloride). Finely ground dissolves better in water than coarse, but under no circumstance use any low-sodium salt substitute or anything that has been augmented with things like iodine - those things are fit for human consumption, but will make your dyeing come out all wrong.
2) Even if what you dye is brand new - in fact, it is even more important if it is new - wash it properly first. New clothes in the shop are frequently inserted with agents to keep them looking nice and neat in the shop, sometimes with light water repellents, and it is essential that these things be washed out before attempting to dye. If the clothes are brand new, I'd even recommend doing it twice just to be sure.
3) Any fabrics that are waxed, waterproofed or fireproofed will not dye properly unless all of those active substances are washed out completely (see point 2). If you're unsure if there is any treatment left in the garment, at least for waterproofing, let a drop of water drip on it. If it immediately soaks in, you're good to dye. If there is any tendency for it to turn into a bead staying on the surface, more cleaning is needed.
4) Modern synthetics can seem quite similar to natural fibres these days, so always check the label to make sure that the fabric you try to dye are at least 80% cotton, linen or viscose. If it is polyester or acrylic, simply forget about it. Those fibres are smooth and dye doesn't attach to them. They are technically possible to colour, but that requires a dye that acts more like a paint covering the outside of it. It exists, but it's a nasty chemical process best left to industrial use. Modern synthetics can seem quite similar to natural fibres these days, so always check the label.
A blend of cotton and synthetic containing more than 80% cotton is usually okay too as that normally means only thin warp threads going in one direction are synthetic for added durability, and they will hardly be visible if there is a major colour change in the dyeing. The dye requires "open" fibres that it can attach to. Silk and wool dyes in different ways, and nylon, which has many things in common with wool, need a different way of making the dyes attach to the fibres, and so you cannot use this particular type of dye for it. There are special ones for silks and wools, some also dyeing nylon fibres.
5) If you want a strong colour, make sure you weigh the textiles to be dyed properly. Especially for black this is critical. Black, for instance, can give the full deep colour to 600g (dry weight) of textiles. If you overstretch that, it will not become black, but a grey. For other colours, this might not be so critical. Also note that there is a maximum weight that can be dyed in one go. If you try to do more, the textiles simply won't get enough room to move freely enough, and it may result in an uneven colouring. Details are on the pack.
6) Any colour in the fabric before dyeing does not magically disappear. It will mix optically with the new colour. If you wish to remove that colour first, use agents made specifically for removing colour before redyeing.
7) Bleach is very efficient in removing colour. So efficient, in fact, that even the tiniest trace of it can ruin a redyeing. If you have got bleach spots on your clothes, most likely they will still be there if you try redyeing - even after several washes. It's usually not worth trying.
8) 99% of all clothes are sewn with polyester thread as it is harder-wearing than cotton. This means that if you for instance have a white garment and dye it any other colour, the threads will remain white. Sometimes this may look fine, but do try to visualise the effect before dyeing to avoid disappointment.
9) The temperature is critical. In the "old days" fabric dyes usually needed 60 degrees to work, but some people, when they saw that what they wanted to dye could only be washed at 40 either gave up on it or tried dyeing it at 30 or 40. What happens if you dye something at 40 that is meant for 60 is that the colour gets a lot lighter. As most dyeing is done to freshen up blacks, that can defy the purpose of the dyeing in the first place. Wool and silk often needs 70 or 80 degrees.
Natural fibres can withstand a few hundred degrees quite well, usually, and the low washing temperature is first of all there to preserve the colours, so when dyeing, do follow the temperature in the instructions, or it won't work. Also, remember to stretch garments properly afterwards as higher temperatures do make them more prone to shrinking.
10) Do not prewash, or set the machine to eco or small load. The amount of dye and salt has been carefully balanced with the amount of water you get in a standard domestic washing machine - which is also why - in this case - 500g is enough regardless of how many packs of dye used.
11) Dye should be put in the drum itself and it should be covered completely by the salt. The textiles to be dyed should be soaked and wet before placing them on top of the salt. This is not essential, but a precaution to make sure that the textiles don't come into proper contact with the dyes before there is more water present to avoid uneven dyeing, especially if the target is a lighter colour.
12) Yes, you can hand dye with a machine dye - probably just as well as with a hand dye - but then you have to make sure that you get the right temperature (see point 9) over a certain time as well as keep the textile moving to dye it evenly - or in a big enough tub to let it float freely. It's not worth the bother. Using a washing machine is the best way to dye fabric at home as it reduces the workload significantly.
Some people are worried about dye contaminating their machine, but if you follow the instructions properly – and your washing machine is clean to start with – any remnants of dye should be gone when you run the machine through two more washing cycles after the dyeing. The first one a regular wash with the dyed clothes still in, the second with an empty machine when one can also use a bit of bleach and a high temperature – though it should not strictly be necessary – to clean out any remaining dyes from it.
If your washing machine is dirty due to other causes, such as limescale, there is a possibility the dye can stick to this, it may require more washes including bleaching to get rid of dye stains, but it's not because of the dye as such but because the machine needed a clean in the first place.
I think that covers the most important things.
In my experience, I can highly recommend this textile dye. For me it worked perfectly for freshening up the black colour of my wife's jeans. She even claims it came out blacker than when it was new.
on 15 June 2015
I love Dylon! And whatever I can lay my hands on, I dye! Dylon is so simple to use, you can't make a mistake. I use this sunflower yellow, every summer, to dye my sofa covers bright again, after the winter. I buy one box for the main sofa cover and another for the cushions and my sofas look brand new again. It's such a lovely, warm yellow and works brilliantly on the cotton fabric. If you're on a budget, you can make all sorts of things look brand new and refreshed again, for a fraction of the price of getting it done professionally or buying new. I buy different colours for different things, my towels, bath mats, curtains, cushion covers, sheets, clothing... Once you start, you begin looking for anything else you can dye!!