A text written by Julian Opie to accompany Julian Opie after Van Dyck, a display at the National Portrait Gallery, London.

First of all I'd like to make it clear that this was not my idea. I would never presume to compare myself to Van Dyck, but when I was asked to make this show next to this great painting, and in one of my favourite rooms, I was very happy to accept despite the risks. They tell me I'm the first living artist to exhibit in this room, which usually shows a selection of lush, worldly yet melancholic seventeenth-century portraits.

I remember when this Van Dyck self-portrait was bought by a London art dealer at auction before the National Portrait Gallery managed to purchase it and I remember thinking how crazily modern and alive it seemed. How humorous and cocky and easy and powerful and huge for its size. The speed and certainty of the paint strokes that both describe and model the skin and hair and cloth, the sparkling light and depth, but most of all you feel his wit and character as he turns back towards you. A head is a very solid positive thing, the opposite of a landscape, it pushes out of the pictorial space and the turning shoulders and flashing glance hurl the image out at you.

I love the portrait paintings of the seventeenth and eighteenth century made in Britain. They are electrifying and inspiring for me. There were similar paintings being made across Europe, but in England the artists seemed to have a particular energy and straightforwardness. Modern curators often focus on the religious or historical works, but I'm not much interested in those. It's the portraits, the standard, workaday, bread and butter works that I respond to. A rectangle of a given size with a head and shoulders or three-quarter length or full-length depending on your budget. Poses, props, clothing and backgrounds interchangeable, probably chosen with the artist’s advice. The paintings had a job to do, to remember an ancestor or marry a daughter or consolidate a powerful landowner, to stand in for someone.

When I'm drawing people I often have sketches of Old Masters on the floor in front of me to get the poses right. I learn from those artists but also I want my works to look like classic portraits. The head portrait is the norm, a circular head in a rectangle of colour, a sign for a painting, for a person, for art.

The National Portrait Gallery focuses heavily on who it is in the picture. I am happy to draw anyone really, though some are easier than others. You can probably tell that some of my pictures are commissioned works and others are stolen images from the street. The commission allows me time and control. I employ a photographer and, in my studio, adjust the lighting and ask the sitter to take up many different poses. I study their features, hair and clothes, make minute adjustments. The street doesn’t allow this level of control but offers me an endless number of models and, crucially, they are not aware of me or by extension you. I simply set up my camera and snap away as the crowds pass. I draw what I see, headphones and tattoos, baseball caps and ruck sacks because that is what is there. I don’t generally bother with the features as the people pass too fast and that is not what you take in in the crush of a crowd.

Van Dyck, like most artists of the time, used oil paint on canvas. These days there are many ways to make an image and I gather options from the world around me, from motorways, airports and shopping malls as well as from museums, ancient ruins and cemeteries. You expect a seventeenth-century painting to be in oils and have a fancy gold frame but now every decision holds meaning and reference. Making a portrait from the same materials as a KFC sign reads very differently from using marble mosaic or laser cut metal, like the name on a ship. I don’t invent techniques, but gather them in the same way I gather the models, and then I mix and match.