I need writing samples for a job interview but don't have any what should I do?

I applied to be a graphic designer at a company and I got a call back but I need to present them with writing samples along with my design work I don't really have any writing samples and I'm not quite sure what to do. I want to whip a couple out but wondering if any writers have suggestions of what an engineering company would be looking for. I know I would be writing content for brochures and ads. Any ideas?