Study for a lab-made Moire pattern-based thread counter

The 32nd International Young Physicists' Tournament (IYPT), a physics competition for students in schools, settled up a problem for the Moire thread counter. The problem mentioned to design an overlay to measure the thread count of the fabric. In this paper, we made one kind of Moire pattern-based thread counter by printing the designed overlay on the plastic paper. As a contrast, we also constructed a self-made CCD camera assisted imaging system and studied the thread count. We used a 1951 USAF resolution test chart and MATLAB software for imaging analysis. Ten kinds of simple cloth were prepared, and their thread count measured. The results and the accuracy of the two methods were discussed.