How does a dandy roll create laid paper and watermarked paper?

The dandy roll is a light, open-structured cylinder covered with wire cloth that rests on the wet web of paper as it travels along the Fourdrinier machine. Its primary function is to compact the sheet and improve its surface finish.12

The roll creates specific paper characteristics by impressing patterns into the moist fibers:

• Laid Paper: When the dandy roll is fitted with wires that produce parallel, translucent lines, the resulting paper is referred to as "laid" paper.23
• Watermarked Paper: When the roll is designed with raised letters, insignia, or other intricate designs, it impresses these shapes into the sheet. This creates a watermark, which is a thinner area of the paper that appears more translucent when held up to light.2

If the dandy roll instead leaves a uniform mesh or crosshatch pattern, the paper is classified as "woven" paper.24