These delicate tissue paper flags are known as "papel picado" or "cut paper/ picked paper" and are handmade in Mexico. They are another of the fabulous handmade traditional arts that flourish all year but particularly around times of important holidays, Christmas, Easter and Day of the Dead. If you've been to Mexico, you may have seen streets draped with these flags before and during holidays or special occasions.
They are made with a chisel and a stencil and "picked" in stacks of 30-40 pieces then strung on string in a long line, mixing colors and loveliness together. It is one of the ephemeral arts of Latin America--made for a temporary time, left to evaporate in the wind and rain after the holiday. A nice reflection of a cultural belief that we can't hold on to anything, all aspects of our lives are temporary, even beauty.
Here's a photo I took on my last trip to Oaxaca. Just walking down the street and turned the corner onto this exuberance.