Abstract: A secure item including a first optical structure and a second optical structure, or an assembly comprising a secure item and another object. The first optical structure including a plurality of blocks and being one of a revealing screen and a combined image. The second optical structure being the other one. Each of the combined image blocks being made up of a plurality of interlaced images. The combined image or each combined image block including a periodic alternation of interlaced image elements. The elements of the interlaced images of a single interlaced image being the same color, but a different color from that of the other interlaced images. At least two blocks of the first optical structure each allowing the observation of a revealed image in each block of a first optical structure, showing different proportions of the interlaced images.