The production of "seal fruit" is based on the condition that plant chlorophyll and anthocyanin must be illuminated in the process of biosynthesis (otherwise they cannot be synthesized), and the peel is specially shaded to make "Fu", "Lu", "Shou", "Xi", "Fa", "Gong Fa", "Auspicious" and "Prosperity" last for more than one year.

When making printed fruits, we first use a computer engraving machine to carve the words of happiness and blessing with black self-adhesive paper. The size of the word is about one third of the height of the fruit. Then, cut the self-adhesive paper engraved with happy words and greetings into small squares slightly larger than each font. When the fruit grows to the maximum volume, try to clean the peels with words in four directions, then tear off four self-adhesive paper with the same festive words or a blessing word from its base paper and paste them on the peels, then remove the self-adhesive paper from the non-font part, and pay attention to pasting the self-adhesive paper font.

When the fruit is ripe and harvested, remove the word self-adhesive paper attached to the peel. Because the pericarp of self-adhesive paper, which was originally pasted with words, was blocked, chlorophyll and anthocyanin could not be synthesized, so the color of the pasted pericarp turned white. In this way, happy words such as "Fu", "Lu", "Shou", "Xi", "Fa", "Shun", "Congratulations on making a fortune", "Happiness is like the East China Sea" and "Longevity is better than the South Mountain" are clearly displayed on the peel, just like being printed on it.

This method of producing "printed fruits" is suitable for apples and watermelons, as well as mangoes, pomegranates and navel oranges.