When I first started working on Julian is a Mermaid I was working on white watercolour paper, using watercolours and pencil. I drew the book this way from beginning to end three times, and sold the book to Candlewick Press with the artwork done on white paper. Now, prior to creating this book I hadn't worked much with colour, my medium was mostly black and white, ink on white paper. But this story was so clearly meant to be in colour, so I had to learn new techniques.

I got better at working with watercolour - I've always loved wet media - but when I would go to scan the illustrations I kept encountering the same problem. I use a lot of negative space in my work (areas that aren't filled in - they're just the blank page), and when I was working on white paper that meant there were lots of areas of the work that were just white. I also have pages that have large areas of washes of colour - particularly the spreads with water - and the tone of the water is a light, sea-foam green. Finally, all of the characters in my book are brown skinned people. So, when I went to scan the artwork, the scanner was either exposing for the characters' skin (a darker value) thereby washing out the washes of seawater, or it would expose for the washes, and then I would lose all this detail in the characters (a blush, little laugh lines around Nana's eyes, that kind of thing).

I realised that the problem was all of this white negative space that was making it impossible for me to have my characters live comfortably on the page. The symbolic connotations of this statement hit me like a brick wall: these black characters were quite literally being erased by white negative space. I had spent the last 13 years working as an actor, and that is what I studied in school. I suddenly recalled a dressing room conversation amongst the black actors at Juilliard on the subject of photographers and lighting designers. So here is what would happen: these actors would book jobs - either for print or in film and TV - and then they would show up on set only to find that the photographer/lighting designer/cinematographer had no experience shooting black people. And you can't light black skin with the same equipment you use to light white skin - you need to reflect golden light, not silver light - however, because the industry standard is for white skin, most professionals never learn this information and the result is that countless black and brown-skinned performers and entertainers have been photographed and filmed looking grey and underexposed. I realized I was having a similar problem, and the cultural significance of this invisible bias towards whiteness felt profound.

That was when I got curious about what would happen if I worked on brown paper instead. I called my art director and pitched the idea of doing all the artwork over on a brown Kraft paper. Although this was a major wrench in the works for her - they had already done all the colour tests for white paper, and because the book was being printed in China this wasn't a quick, overnight process - she never let on, and just said ‘get me a sample and we'll try to figure out how to print it.’ I am so grateful for her flexibility because as soon as I started working on the brown paper it felt completely inevitable, and the characters finally felt at home.

Julian is a Mermaid is published by Walker Books.