Dark background with bright text also make people feel the perception of contrast, which in essence is very attractive and can cause irritation. The black text to white at the same time must reduce the brightness of the background, to reach a certain intensity gradients in order to bring out the white text. Different color paper wholesaler of light incident on the physical changes. In the visible spectrum, the green light wavelength of about 490 ~ 570nm, living in the middle part of the visible spectrum, is the most comfortable visual function of the "camouflage", which is conducive to calm nerves, gives rise to the feeling of calm and quiet, make passionate emotions tend serenity helps the absorption of knowledge and the strengthening of concentration.

When printing in black and white to white on green background lead type, the white text can be generated to attract the attention of students to non-spontaneous effect; And not only does not form a green background adverse visual stimulation, but also in the eyes of the students watched the text and feel comfortable green environment, the combination of both will help focus students' attention and understanding enhanced; help improve visual performance and prevent visual fatigue early appearance, effectively extending the normal ongoing with the eye, vision for the protection of young students has far-reaching significance.

2.4 beans green paper

In recent years, special type of color paper wholesale red paper increasingly used children's color paper wholesaler paper wholesalers in which the reaction is the largest Chinese Children's Publishing House of the "21st Century Children's Encyclopedia." This color paper wholesaler paper wholesaler is the first use of green beans printing paper color paper wholesaler paper wholesalers, improve paper quality, protecting the children's vision. Ministry of Education of children whiteness of paper, but should be in the 75% to 76% (UNESCO