Wow Plastidip for shoes is a first for me. Usually hear this for cars. Good info thanks
1 can Plastidip aerosol spray in Black - ~$30
Masking tape/Painter's tape - ~$1-$8
Old newspaper - Free
Didn't take any pics of the process but you can easily google it.
General steps:
1) Using the tape, tape around the area of the boost, making sure to leave about 0.5mm gap between the tape and boost. Depending on whether you want to black out the heel cup, you can tape around it as well.
2) Use the newspaper and tape to cover the remaining areas of the shoe so that your paint doesn't get onto those areas.
3) Start spraying with the plastidip. Use light coats and spray a total of about 4 coats, leaving about 10 mins for each coat to dry before spraying the next coat.
4) After you spray the 4th coat, wait for about 4-5mins and start removing the tape slowly. Those that have used plastidip before will know how it works. Those that don't, go read up and see youtube videos before attempting.
It takes some practice to get the spraying right, the fundamentals of doing air-brushing, spray painting applies the same way. So if you are a 1st timer, be prepared that you will cock up. Try on some random objects 1st before attempting on your beloved shoes.
Make sure you cover sufficient area around your spraying area with newspaper to avoid vandalizing the place, especially if you are doing it in a public area.
As for how long it will last, only time will tell. Some people on reddit have said that it's pretty lasting. As with all things, don't try to rub it on kerbs and stuff and you should be alright. Touchup should be fairly easy to do, just tape around the touchup area and cover the rest and spray 1 or 2 coats.