Patent ID: 7390557

Claim:
A method for manufacturing a coated web of paper or paperboard, comprising the step of: applying droplets of a web treatment substance to at least one surface of a moving web of paper or paperboard by spray-coating to form a web treatment substance layer thereon, wherein the web treatment substance comprises coating pigment particles, and wherein at least droplet size and viscosity of the web treatment substance are controlled to achieve an optimal spreading behavior of the droplets on the at least one surface of the moving web of paper or paperboard such that thicknesses of the web treatment substance layer in two randomly chosen sample areas of the spray-coated at least one surface of the web are essentially equal when each of the sample areas is selected such that a smallest dimension across said each of the sample areas is at least twice the thickness of fiber in the web, whereby the web treatment substance layer has a surface contour which conforms with a surface contour of the at least one surface of the web.