Offset Brochures are those that requires volume orders. They come in several sizes like A4, A5 or A6. These orders are usually 1,000 per and above. It is wise to order it more as the cost of production is cheaper as volume grows. Small orders like less than a hundred are done by digital offset.
Offset brochures are good in coated paper which comes in C2S#80, 100 or 120. This depends on the product and the content.
Some brochures are magazines type in several pages. Those are required for products that have more technical date.