A flyer usually has a relatively short lifespan, such as being used to announce a one-time event like a grand opening or special promotion. So, the paper used for flyers does not necessarily have to be heavy weight paper. However, a flyer can be printed on thicker paper to make it more durable if it contains information that will be referred to again and again, such as when used as a product spec sheet or instructions.
Brochures are generally not distributed as freely as flyers. Usually brochures are distributed by salespeople only after some initial interest is shown by a potential customer. This is because more money is typically invested in a brochure than in a flyer. A brochure must be of top quality since its job is to help showcase a product, highlight a service or promote a company. When making a purchase decision, your customers will compare the quality of your promotional literature to those of your competitors so brochure printing should not be skimped on.