In order for him to look authentic in the sense that he comes across as our chosen indie artist, the clothes he wears is an important factor of his image. Most indie artists wear quite casual clothing, with the likely hood that some of it is one off pieces found in vintage shops like Rokit, Beyond Retro and the Renewal section in Urban Outfitters. This mixture of a casual high street, vintage mix presents a look which is individual to the person. Below I made a little mood board gif of the style I see our artist dressing like.
Jack will definitely be wearing dark skinny jeans as these are a great base trouser to style and work with. I think the colour pallet he should wear should be quite earthy with out doors colours such as burgundy, navy, dark green and blues. These all compliment each other well. Layering will play a big part of Jacks image, through tees, shirts, jumpers and a coat. Vans will be a suitable shoe choice as they are instantly recognisable and a lot if his fans will wear these too. Below is an outfit set I created on polyvore, this gives a good idea of what we expect Jack to wear, I know he has a few similar items to the ones below anyway.
