A corrugated sheet processing apparatus comprising: sheet processing equipment comprising a corrugator and at least feed and guide rollers for selecting, moving and supporting sheets or webs to the corrugator for forming a corrugated sheet from which corrugated products can be cut, at least one layer of the corrugated sheet, and thus of the products, being formed from a printed sheet or web; and a control system for controlling the sheet processing equipment; the corrugated sheet processing apparatus further comprising a visual inspection unit arranged for reading printed markers provided on at least one printed sheet or web as the printed sheet or web, and thus the printed markers to be read, pass through the corrugated sheet processing apparatus, or the corrugator thereof; wherein: the corrugated sheet is for more than one product order, the products of one order compared to a previous order having differing details, comprising any one or more of a) differing shapes, b) differing forms or types for at least one of the sheets or webs, c) differing numbers of webs, and d) differing glue types, glue temperatures, glue thickness or glue locations; the apparatus being characterized in that: the printed markers are printed information markers having information thereon; and the control system further has a data look-up table comprising for the products to be cut from the corrugated sheet at least information associated with the said differing details, and associated with that information identifier information readable from the printed information markers by the visual inspection unit, whereby the apparatus can identify what products will need to be produced downstream of the visual inspection unit, and identify in advance the required settings for the sheet processing equipment or corrugator for those products, in response to a read printed information marker so that the sheet processing equipment or corrugator can be appropriately controlled by the control system to meet the said required details of the identified product. sheet processing equipment comprising a corrugator and at least feed and guide rollers for selecting, moving and supporting sheets or webs to the corrugator for forming a corrugated sheet from which corrugated products can be cut, at least one layer of the corrugated sheet, and thus of the products, being formed from a printed sheet or web; and a control system for controlling the sheet processing equipment; the corrugated sheet processing apparatus further comprising a visual inspection unit arranged for reading printed markers provided on at least one printed sheet or web as the printed sheet or web, and thus the printed markers to be read, pass through the corrugated sheet processing apparatus, or the corrugator thereof; wherein: the corrugated sheet is for more than one product order, the products of one order compared to a previous order having differing details, comprising any one or more of a) differing shapes, b) differing forms or types for at least one of the sheets or webs, c) differing numbers of webs, and d) differing glue types, glue temperatures, glue thickness or glue locations; the apparatus being characterized in that: the printed markers are printed information markers having information thereon; and the control system further has a data look-up table comprising for the products to be cut from the corrugated sheet at least information associated with the said differing details, and associated with that information identifier information readable from the printed information markers by the visual inspection unit, whereby the apparatus can identify what products will need to be produced downstream of the visual inspection unit, and identify in advance the required settings for the sheet processing equipment or corrugator for those products, in response to a read printed information marker so that the sheet processing equipment or corrugator can be appropriately controlled by the control system to meet the said required details of the identified product. the printed markers are printed information markers having information thereon; and the control system further has a data look-up table comprising for the products to be cut from the corrugated sheet at least information associated with the said differing details, and associated with that information identifier information readable from the printed information markers by the visual inspection unit, whereby the apparatus can identify what products will need to be produced downstream of the visual inspection unit, and identify in advance the required settings for the sheet processing equipment or corrugator for those products, in response to a read printed information marker so that the sheet processing equipment or corrugator can be appropriately controlled by the control system to meet the said required details of the identified product.