For the better part of this year, I’ve lived out of a suitcase, travelling for work and research, with holidays here and there. When the trip I’m currently on was extended from five weeks to several months, it became a real test for the outfits I packed and my need – as someone who thinks about fashion a lot – to look and feel fresh.

Everything has been on very high rotation, but the two items I’ve worn the most are a black high-necked ribbed black jumper with a zip front and a black pair of pants with an elastic waist. I wear them on flights and trains, when I’m writing at home, to and from yoga and on my morning coffee run. I even drove halfway across California in them to visit a flax farm. Because of their architectural, roomy cuts, they look chic but feel comfortable, which is why I wear them so much.

But whether it’s the hard washing or the hard wearing I’ve put them through, their colour has faded. Both Garments are made of cotton, which tends to be less colour-fast than other materials, but (as I’ve learned from experts on dyeing clothes) cotton absorbs dye better too.

Rather than buying something new, I decided to restore them to their former, dark shade of black. I consulted Neuw Denim menswear designer Jason Hewitt on the best and easiest way to overdye them. He recommended a packet dye that could be put through the Washing Machine.

Crosscheck the label (and the machine)

“Firstly, always check the fibre content of the garment you’re dyeing and make sure you are using the correct dye for the job,” Hewitt says.

According to the packet instructions, the dye I’ve bought can be used for cotton, linen and viscose but not wool, silk, polyester or nylon. It warns that garments made from blends of these materials will result in a lighter shade and the blend should be less than 20% of the total.

It is also important to make sure the dye is intended for the type of washing machine you have. I needed one that would work with a front loader.

Check your threads too

If you want to dye a garment with contrast stitching, the results may vary. “Since most threads are polyester, when dyeing anything of any colour but especially black, the threads don’t take the dye that well,” Hewitt says.

The threads on both my garments are also black, as is the zip on the jumper. Although I’m not sure what they’re made of, because they are the same colour as the rest of the garment and there are no details in the stitching that could show up badly, I’m not worried about this.

But I make sure to take photos of the garments’ care labels in case these turn black and become illegible.

And do a water-temperature check

Hewitt says it’s really important to dye garments at the temperature specified on the packet but also to make sure you reconcile this with the instructions on the care label of each garment. If the dye calls for a higher temperature wash than the care label, there’s a risk of shrinking or damaging the garment.

This gives me pause, as I didn’t do this before I bought the dye. Both garments require a cold wash but the dye packet says to wash them at 40C. Ultimately, I’m confident in the quality of the cotton and think this shouldn’t hurt, but if they were made of different fibre blends, especially wool or silk, I may have stopped here and been annoyed at myself for wasting money on a dye I couldn’t use.

The process

The dye’s instructions say the garments must be clean and wet, so I put them through a wash cycle. Then I unwrap the dye – which is basically a plastic ball with a hole in the top and powder inside – peel off the lid and place it on top of the wet clothes, as per the instructions, and put them through a cycle. It is a very neat and easy way to get the right amount of dye, with very low risk of spillage or mess. But I do take off the expensive red, cream and blue striped knit I’m wearing and put on a black T-shirt – just in case.

Rinse and repeat

When the cycle is done, the empty pod needs to be removed. The instructions say to add some laundry detergent, then run another wash cycle at the same temperature.

Dry the garments

Once washed, dyed and washed again, the garments are ready to dry in the shade, away from any direct sources of heat. I spread both on a clothes horse and smooth out any creases.

Clean your machine

Cleaning the dye out of the washing machine is essential to avoid a laundry disaster the next time it is used. Hewitt says to run the empty washing machine through another cycle at 40C or 60C to ensure all the dye is drained out. “It’ll be a real tragedy if you put a load of whites on and they come out grey.”

The results

The garments have definitely returned to a more intense black, which is what I wanted. The pants, which are made of a thin cotton twill, seem to have taken to the dye better than the jumper, which is made of a thick ribbed knit so it is much denser and has a lot more yarn to dye. But the pants had also faded more, so it’s difficult to compare them like for like. The care labels on both garments have turned completely black.

I’m a little concerned by the amount of water and energy the process required – given that it took four wash cycles. However, this unease is alleviated by a quick comparison with the amount of water used to make new clothes.

The average front loader washing machine uses 50 litres per cycle, so all up I used 200 litres of water. In Australia, it takes on average 2,400 litres of water to grow one kilogram of cotton, according to Australian Cotton – which makes it some of the most water-efficient cotton in the world. But it’s unlikely Australian cotton was used in either product (although they are both from Australian designers). The jumper is organic cotton, which is not grown in Australia, and the pants have a Better Cotton Initiative certification, which indicates higher standards for farming that could align with Australian standards – but it’s hard to say.

So if you consider that new clothes would also require water to be dyed and treated, redyeing old clothes uses just a fraction of the water. And as someone born and raised in Melbourne, there is something extremely satisfying about restoring black garments to a true black black.