Do I need to stretch watercolour paper?

Stretching your watercolour paper before painting allows you the creative freedom to use as much water as you want, whenever you want. To avoid unsightly cockling – the wrinkling and ridging of the sheet that’s notoriously difficult to fix – it’s essential to stretch your paper, especially if you plan to use a lot of water. However, if you’re working on heavyweight paper stretching may not be necessary.