Throughout history, printing processes have had a substantial change, moving from manual to highly automated ways. Below is a summary of several important printing procedures:One of the earliest methods is relief printing, which is applying ink to paper by moving it from elevated surfaces. Two popular techniques for relief printing are woodcut and letterpress. While moving type is used in letterpress, images are carved onto a wooden block in woodcut. A mirror image is produced on the printing surface using both techniques.Creating an image on a plate—usually made of metal—by cutting it out and then filling the spaces with ink is known as etching. After wiping the plate clean, the ink is only left in the nooks and crannies, where it is pressed onto paper. Aquatint, etching, and engraving are common intaglio methods.Lithography: The foundation of lithography is the idea that water and oil repel one another. This method involves drawing the image on a flat surface, usually a metal plate or limestone, using a grease substance. After that, a chemical solution is applied to the plate, which sticks to the oily picture but repels water. Ink is repelled by non-image areas and is attracted to image areas when inked. In one form of this process called offset lithography, the inked image is first transferred from the plate onto a rubber blanket and then onto paper.Screen printing is the process of applying ink to a substrate by means of a stencil, or screen. Using a squeegee, ink is pushed through the fine mesh screen that holds the stencil to the substrate. Screen printing is useful for bright, multicolored designs on a variety of surfaces, such as textiles, posters, and signage, because each hue requires its own stencil.Digital printing is the process of printing digital information directly onto a substrate using a variety of methods. Two popular digital printing techniques are inkjet and laser printing. Whereas laser printers employ toner and electrostatic charges to form images, inkjet printers spray tiny droplets of ink onto the substrate. Variable data printing capabilities, quick turnaround times, and flexibility are all provided by digital printing.These printing techniques offer special qualities and uses that meet a variety of printing requirements in a variety of industries, from advertising and textiles to publishing and packaging. Technological developments keep refining these procedures, enhancing printing industry sustainability, quality, and efficiency.
