Every September, Marissa Dawson’s home starts filling up with model trains. About 11 years ago, she started painting the trains for NorthPark’s annual Ronald McDonald House of Dallas fundraiser. “In 1998, a family friend asked me if I would be interested in painting a couple just because she knew I like painting and drawing,” says Dawson, who lives in Cochran Heights. “So I did three trains the first year, and I’ve been doing it ever since.” Now she paints as many as 100 trains per year. Sponsors can pay $175 per train, and at the end of the season, they get to keep the train. And they can specify in the order what design they want, such as a corporate logo. “My favorite train of all times is when a woman wanted Garfield in a Santa hat,” she says. “A guy last year wanted a snowman in cowboy boots.” She tries to make each one unique, which can become difficult for Dawson, who admits she’s not an artist. “My designs aren’t that great,” she says. “But if I see something, I can kind of copy it and make it my own.” The trains at NorthPark are on display through Jan. 3. Admission prices are $6 for adults, $3 for children and adults older than 65.