For laptop

Metal chain or nylon, size 8 or above, with a metal puller. The main zip is the failure point on almost every backpack that breaks, and size 5 plastic zips don't survive a year of daily use.

By measuring it. A fifteen-inch compartment from one manufacturer isn't the same as another's: if the company is handing out a specific model, it's worth measuring width, height and thickness with the sleeve on. It's the most common reason for returns. And watch out for the litres in the catalogue, which are measured with the backpack fully inflated.

Embroidery. On technical fabric it withstands rain and rubbing better than any printing. It costs more, and it's worth it.

The back panel and the straps. A back panel with foam and ventilation channels completely changes how it feels on a thirty-minute commute. The straps should be wide at the shoulder and narrow towards the bottom, and include a chest strap if the backpack is for travel.

Yes. If you tell us what laptop your people use and whether it's for the office or for travel, we'll propose two models with a sample.