unaided eye 托福

Flashing microtext that, when viewed with the unaided eye, appears to be part of the line design, bet under magnification is seen as a repeated pattern of words, codes or numbers.

通过使用微缩文字，来增加防伪特征。闪烁微缩文字，在没有使用放大情况下，只是一条线，在使用放大时，可以连续重复文字、编码及数字等。