In Runescape, a knife can be used on logs to cut them into longbows(u) with respect to their type which sell for a higher price on the Grand Exchange and to general stores than the logs themselves. A player can cut up to 1,500 logs every hour while paying little attention to the game.
For profit, Maple logs are best to cut into longbows because the differences between all logs and their respective longbow(u) are all around 30 gp and cutting maples requires the smallest investment while still producing a product that will sell – this method is about 45k gp/hr.
Higher level fletchers can cut magic logs which have a slightly higher profit margin of around 40 gp and are significantly quicker experience but requires substantially higher startup money. Cutting Magic logs brings in about 60k/hr.