Woodblock printing is a relief technique.

The wood surface is carved. Ink is rolled onto the raised surfaces. The carved places will not print.
Paper is placed ontothe inked board and run through a press or rubbed with a spoon or brayer.

The Provincetown Print: Whiteline woodblock

Some of the samples below have been done in the whiteline Provincetown Print Style which originated around 1914.
A group of Cape Cod artists collaborated as this technique evolved. Among them, Blanche Lazzell, BJO Nordfeldt, Ferol Warthen...
Typically in woodblock prints, dark printed lines outline the colorful shapes. In the P-town print, white lines delineate color.