I had a major wardrobe clear-out about a week ago and now have a pile of things I need to fix, or turn into something else.
This t-shirt will probably be the first of many that will get turned into a tank top.
Here's how I did it.
1) Take your t-shirt and down the sides from the top of the sleeve. How far down you go will depend on how you want to wear the tank top, I wanted to wear it with another vest top underneath so mine reaches down past my ribs. Make sure you do not cut too far towards the bottom of the shirt though, otherwise you'll have little material at the bottom to hold the shirt together as a tank top.
2) Lower the neckline of the t-shirt, making sure you only cut the front neckline then save this piece for later. You can stretch the fabric for a 'drape' neckline effect.
Turn the t-shirt over and cut a 'V' shape into the back of the neckline. How big this neckline is depends on how thin you want the straps, but preferably keep them thick to make the next stage easier.
3) Take the spare neck piece from Stage 2 and place it under the 'V' neck area. Gather the material from both sides of the back of the t-shirt; then using the neckpiece, tie a tight knot at the base of the 'V'. This will create the knotted back.
Cut off excess fabric in the knot, if you want it to be more secure you can sew the knot to the t-shirt.
The back of the top should now look like the image below.
5) Tidy up and cut off any excess fabric, adjust the knot to suit your taste. And there you go!