Posters have been a popular and effective advertising and informational medium since the invention of paper. The earliest posters were hand-drawn, eventually giving way to commercial printing processes such as screen printing, letterpress and offset lithography. It was not until personal computers and printers became widely available in the early 1980s that poster printing could be accomplished in-house. With ensuing leaps in computer technology, computer printers also enjoyed advancements, allowing poster printing to reach a level of ease and quality once only possible with commercial methods.
Poster Size
The first consideration in choosing the right poster printer is the average size you'd like to produce. Most all desktop computer printers are capable of printing up to letter and legal-size posters (8.5 by 11 inches or 8.5 by 14 inches, respectively) with small number of consumer printers able to print ledger size (11 by 17 inches). Printing sizes larger than 11 by 17 inches takes you into the commercial digital-printer realm. Commercial printers, available in numerous sizes and configurations, are able to print posters up to billboard size. These printers, called large-format printers, require powerful computing power, and are usually equipped with an auxiliary computer for processing the image, called a RIP, or Raster Image Processor. RIPs are necessary to rasterize, or create a bitmap of the image, which converts the image size into high-quality information required by the printer to operate. External RIPs are not necessary for consumer printers because the poster image size is small enough for the printer's program to RIP the file internally--a process that is transparent to the user.
Paper Stock
All printers are limited to the type and weight of paper stock the machine is capable of handling. Consumer printers are limited to office paper and light card stock, but large-format printers are able to print a wider variety of materials and weights. Specialty flat-bed large-format printers can print on rigid stock, including metal sheeting, plastics and wood while conventional large formats are limited to roll material, such as paper and canvas, with some able to print on rolled adhesive vinyl, other plastics and fabric sheeting.
Finishing
A common drawback with all computer poster printers is the durability of the ink and material (also called substrate). Although some printers are now available with more robust solvent-based inks, dyes and waxes, most consumer printers and a number of commercial large-format machines use water-based ink. Posters can be made more durable by the addition of a clear, frosted or tinted laminate sheet. Applied either hot or cold by hand or machine, laminates help preserve the poster from abrasion, moisture and the fading effects of sunlight.
Printing Types
Most poster printers are of the ink-jet variety, similar to a standard computer printer. But other ways of getting the image onto the substrate are as ingenious as the printers themselves. Dye sublimation, thermal wax and thermal ribbon printers use a method of heated pigment transfer, rather than liquid ink, to apply the image to the substrate. These printers offer bright and durable colors when longevity of the poster is desired and are normally used for a specific poster use, image type and application.
Which Poster Printer Is Right For You
Choosing the right poster printer is a subjective matter. Deciding on the size, substrate, use and application are the first steps, followed by cost of the machine, supplies, materials and auxiliary equipment. For occasional use of poster up to 11 by 17 inches, a suitable consumer printer with a desktop laminator of suitable size is a relatively inexpensive and useful setup. Expect the total investment to be well under $1,000, not including the computer.
For larger sizes, the cost of equipment and materials may be too expensive for occasional poster production but is a worthwhile investment if you're planning to start a large-format printing business. In this case, market research and further study of the technical specifics of available systems is in order because a basic printing system can easily start in the area of $8,000 to $10,000.
