| 摘要 |
A reading material with hidden explanatory notes, in which a text is composed with word symbols of a certain kind of language and is provided with corresponding explanatory notes, word symbols or coding marks, at a place corresponding to the text, wherein the said notes are printed with colourless fluorescent printing ink or a kind of printing ink similar to the paper to be printed in luster and the colour of the spectrum so as to be in a hidden state. The hidden notes become distinguishable by eyes or an optical testing means when the contrast in colour and luster between the notes and the said paper is shown under some physical and chemical action applied by a display device. |
