What is postscript?

PostScript is a programming language that tells printers and other devices how to draw text and images on a page. Think of it as a set of instructions that describe the shapes, colors, and layout of a document, which the printer then follows to produce the final printout.

Let's break it down

  • It’s a page description language, not a word processor.
  • The code is written in plain text, using commands like “moveto”, “lineto”, and “show” to place graphics and text.
  • When you send a file to a printer, the printer’s interpreter reads the PostScript code and renders the page exactly as described.
  • PostScript can handle vector graphics (shapes that scale without losing quality) and raster images (pixel‑based pictures).

Why does it matter?

Because it gives designers and developers precise control over how a page looks, no matter what printer or screen is used. This consistency is why PostScript became the foundation for professional printing, PDFs, and many desktop publishing workflows.

Where is it used?

  • High‑end laser printers and large‑format plotters.
  • Desktop publishing software (like Adobe Illustrator and InDesign) when exporting files.
  • The creation of PDF files, which embed a subset of PostScript.
  • Some graphic design and CAD tools that need exact page rendering.

Good things about it

  • Device‑independent: the same PostScript file looks the same on any compatible printer.
  • Supports scalable vector graphics, so designs stay sharp at any size.
  • Powerful: includes loops, conditionals, and variables, allowing complex page layouts.
  • Widely adopted in the printing industry, making it a reliable standard.

Not-so-good things

  • Learning curve: it’s a full programming language, which can be intimidating for beginners.
  • Large file sizes for complex pages, especially when many high‑resolution images are included.
  • Not as common on everyday consumer printers, which often use simpler languages like PCL.
  • Rendering can be slower on low‑power devices because the printer must interpret the code before printing.