The Croatian interlace is a design that includes loops and knots, kind of like a big knot of spaghetti. It was often used in ancient Croatian art, such as on pottery, jewelry, and other decorative items.
Imagine that you have a piece of string in your hand. You can take that string and make a loop, then another loop, then cross the string over itself and make another loop. You keep doing this until you have a big, tangled knot of loops and lines. That's what the Croatian interlace looks like!
The designers who made these patterns would often start with a basic shape, like a square or a circle, and then build the interlace around it. It's kind of like drawing a picture, but instead of using lines and shapes, you're using loops and knots.
The Croatian interlace was popular because it was a really cool way to decorate things. People liked the way it looked, and it made ordinary items like pottery or clothing feel more special and important. Even today, you might see examples of the Croatian interlace in modern art, clothing designs, and other places.