The present study is concerned with how frame size influences the apparent length of a line enclosed within the frame. The square, as one of the simplest geometrical figures, served as frame. Five different sizes of the square were employed. The lengths of the lines in the middle of these squares were compared with the constant line of 50 mm on the constant square 7 x 7 cm. The results indicate that the frame greatly influences the apparent length of the line. The phenomenal length of the line is a logarithmic functon of the area and the side of the squared shaped frame. Observations made during the course of the experiments indicate that in the line-frame articulation the frame influences the line not only in a horizontal direction but also probably in a vertical direction.