I don’t know if this is even allowed but this is way too useful not to share so I am risking prosecution (okay, OA!) and copy-pasting this very educational information sheet on the different printing processes from Tinyprints, a site that specializes in baby announcements.
Frankly, this is the first detailed explanation of the various printing processes that I actually understood (so thank you, Tinyprints, truly!). I just added some samples to make the distinctions clearer to other printing dummies like me. It’s really important that we dig the printing process because it is essential in choosing our wedding invites. It will determine the cost and class of the invitations.
So help yourself:
Offset Printing (Flat Printing)
This process is often called flat printing. In offset printing, the ink appears to lay flat atop the paper. It’s less expensive than engraving or thermography, and creates a less formal look. A metal or paper plate is imaged from a black and white image, typically from a laser printer. The plate is treated so that the ink adheres to the image. The plate is then hung on a press, and the image is transferred onto paper.
The digital press delivers high resolution digital color that rivals the traditional offset printing press used on most stationery. The print quality is similar to offset printing (flat printing) with bright, long-lasting colors. Digital offset printing is the latest technology in the color printing industry offering the quality of traditional offset printing, but capitalizing on the efficiency of a digital workflow.
Developed during the 1700s, engraving is still the most formal and classic printing process. Engraved invitations will have a distinct look and feel that is easily recognizable; however, it is also the most expensive. The paper is pressed against a metal plate, which causes the letters to be raised on the paper. You can feel each character when you run a finger across the back of the paper. The raised letters in a matte ink finish produces an indentation on the reverse and a gentle wave or ripple on lighter papers giving it a look of distinction.
Resulting in a raised or three-dimensional print effect, this popular printing process attempts to emulate the finished quality of engraving. Thermography is a simple process used in conjunction with any conventional wet-ink printing press. The printed sheets coming off a press pass through a powder application, where resin is applied to the wet ink. The resin is then removed from all areas, except where it adheres to the wet ink. The paper is then heated causing the resin to melt and fuse to the ink. The substrate is then cooled, which finalizes the process. Since there is less manual labor required, thermography is a much more cost effective solution for raised printing than engraving. However, stationery with classic engraving still tends to have a fuller complete raised printing effect. The letters from a thermographed print are shinier than engraved characters.
A die is created and pressed against a special kind of foil that transfers the design onto paper, under heat and pressure. Foil-stamping is used to make complex images and prints.
Also called blind embossing, this process creates a raised impression on a sheet of paper by pressing the paper between two heated metal dies. One die fits into the other mirror-image die like a lock and key. The embossing is termed “blind” because the design is formed without ink or foil. Debossing is an image stamped onto paper without ink or foil and it appears indented. Embossing is ideal for elegant design motifs and print.
The letterpress was invented by Johann Gutenberg in 1450. Since it is very time-consuming compared to more modern processes, high quality letterpress printing has become rare. Metal type is set into a frame, which is put into a press and produces a matte ink design or lettering that is sharply impressed rather than raised. Because the letterpress does not touch the surface of the paper, letterpress can use soft, embossed or highly-textured papers. Letterpress designs are often simple yet elegant designs with a distinct look and feel.
If you have good penmanship and enough time, you can buy stock announcements and envelopes and write your personal notes by hand. The downside is that writing announcements and other occasions by hand is generally perceived as less formal.