| - Feature of Inkjet |
| |
| Commercially available packages of inkjet papers are sold under various product descriptions such as glossy paper, photo-quality paper, photo paper, coated paper, matte paper, plain paper, non-coated paper, etc. This is because the manufacturers all use different product category descriptions. Below is a brief explanation of inkjet papers. Inkjet papers can be classified as shown in the figure below. There are also some products that are not paper. Material for inkjet printing as a whole, including non-paper media such as cloth and film, are referred to as "inkjet media." |
| |
| - Plain paper and coated paper |
| |
| Classification is made depending on the existence of an ink receptor layer to absorb ink from an inkjet printer. Papers with no ink receptor layer are called "plain paper" or "non-coated paper," and those with an ink receptor layer are called "coated paper." Coated papers are greatly superior in image quality and color because their ink receptor layer is developed taking into consideration color development and fixing of ink. Coated papers are classified into several types such as glossy, non-glossy, etc., depending on the different kinds of surface. All plain papers have non-glossy surfaces, and are inexpensive. Plain paper is suitable for the printing of color data that mainly consists of text. Printing on media other than paper -- such as film, cloth, and metal foil -- becomes possible by forming an ink receptor layer on the material's surface. |
| |
| - Plain paper and coated paper |
| |
 |
Coated papers are designed exclusively for use with inkjet printers to achieve the best image quality. Inkjet papers of this type are the most popular on the market. The picture below is a cross-sectional view of our representative inkjet paper.
Coated papers are classified into several types such as "glossy paper," "semi-glossy paper," and "matte (non-glossy) paper," depending on the different features of their surfaces. Any of these papers can produce high-definition and quality full-color images.Glossy papers, having the same quality as cast-coated papers, are very glossy.Semi-glossy papers, having the same quality as art papers and A2 coated papers, are only slightly glossy. With regard to products other than paper, film products are also classified into the glossy type and matte type. The picture below is a cross-sectional view of a representative glossy paper. |
|
| |
| - Photo-quality paper/photo papers |
| |
 |
Among commercially available papers, photo papers are the most expensive. The "ink receptor layer" is formed on the surface of the photographic printing paper. Inkjet papers of this type are similar in quality to conventional photographs. As they are developed to print photographs by inkjet, prints of the highest quality and definition can be produced. The storage stability of printed materials is well considered. Inkjet papers of this type, including film and cloth products, display differences in performance, depending on the material from which the ink receptor layers are made, due to differences in ink absorption. |
|
| |
| -Storage of inkjet prints |
| |
Until recent years, the storage stability of inkjet papers used for drop-on-demand printing was not a priority. However, along with an increase in the use of inkjet prints for graphic design and output of photographs using digital cameras, inkjet print storage stability has become a requirement. Various technologies are used to improve the storage stability of inkjet papers.
Explanations of items listed below are as follows: 1) Water-fastness 2) Light-fastness
1) Water-fastness
Most inkjet inks are water-soluble, and therefore, if printed materials become wet, water-soluble inks are easily redissolved and the image may fade. In a high-humidity environment, inks are also redissolved and phenomena such as image running are caused. Various measures for improvement are being implemented to prevent ink dissolution. One commonly-used method is the electrostatic method. Generally, inks are negatively charged. In the electrostatic method, by applying positive charge to a sheet of paper, negatively charged ink adheres to the paper by electrostatic forces. (See the figure below.) |
|
|
2) Light-fastness
Ultraviolet radiation and ozone cause fading in the colors of inkjet printed materials, and further improvements in inks have been required. The quality of inkjet papers, however, is improving. In recent years, inkjet printed materials have been developed that can be stored for several years indoors assuming the best combination of ink and paper. Color fading is considered to occur due to decomposition of pigments by active oxygen generated by ultraviolet light or ozone. Improvements are being made using light stabilizers, antioxidants, and other methods (see the figure below). |
|
|
 |
| |
|
