Plaid is a pattern of crisscrossing horizontal and vertical stripes in different colors, creating a grid of squares and rectangles. You've probably seen plaid on flannel shirts, school uniforms, or picnic blankets. The stripes overlap to form blocks of color, like a woven checkerboard with multiple colors instead of just two.

The pattern is strongly associated with Scotland, where different clans (family groups) wore their own distinctive plaid designs called tartans on their kilts and other clothing. Each clan had its own unique combination of colors and stripe widths, so you could tell which family someone belonged to just by looking at the pattern.

Today, plaid appears everywhere: on backpacks, scarves, skirts, and even wrapping paper. Buffalo plaid (bold red and black squares) is popular for outdoor clothing and decorations. Plaid gives things a casual, comfortable feeling, which is why it shows up so often on cozy flannel pajamas and shirts.

The word plaid can refer to the pattern itself or to fabric with that pattern. You might say “I'm wearing a plaid shirt” or simply “I'm wearing plaid.” Some people confuse plaid with other patterns like checks or gingham, but plaid typically uses more than two colors and has stripes of varying widths.