Carbon free copy paper, also known as pressure-sensitive paper or NCR paper (No Carbon Required), is a special type of paper that can leave clear handwriting on multiple documents without the need for traditional copy paper. It is widely used in commercial, office, banking, taxation and other fields, especially in scenarios where multiple copies of invoices, receipts, orders, etc. are required, carbon free copy paper provides great convenience and efficiency. So, how many layers does carbon free copy paper actually consist of?
Carbon free copy paper is usually composed of three layers of paper, each with its specific function:
1. Top layer paper (CB paper): This is the layer of paper directly written by the writer, with a layer of microcapsules coated on the back, which contain colorless dyes inside. When writing or printing pressure is applied to this layer of paper, the microcapsules rupture, releasing dye and forming text or patterns on the underlying paper.
2. Intermediate layer paper (CFB paper): The front of this layer of paper receives dye from the top layer of paper, and the back has microcapsules to continue transmitting information when there are other layers of paper below. The function of CFB paper is like a bridge, ensuring that information is transmitted from the top layer to deeper layers.
3. Bottom layer paper (CF paper): This is the bottom layer of paper, which is only coated with a color developing agent on its front. When the dye comes into contact with the color developing agent, black or other colored text or patterns will appear. If only two copies are needed, the bottom paper will directly receive information from the top layer; If there are more layers, it serves as the endpoint for information transmission.
It is worth noting that although standard carbon free copy paper typically consists of three layers, in practical applications, there can be combinations of two, three, or even more layers depending on the requirements. For example, in some simple double documents, only CB paper and CF paper may be needed, without the need for intermediate CFB paper. In more complex multiple documents, multiple layers of CFB paper may be required to ensure accurate information transmission.
The invention of carbon free copy paper greatly simplifies office processes, improves work efficiency, and reduces the environmental impact of traditional copy paper. It is a significant technological innovation. With the development of technology, although electronic documents and digital signatures are gradually replacing paper documents, carbon free copy paper is still irreplaceable in certain specific situations. It continues to serve various fields of modern society with its unique advantages.