Exporting Vector PDFs from Processing Sketches

Problem: You need a scalable, editable output from a Processing sketch

When you want to send a sketch to a print house, import it into Illustrator, or include it in a LaTeX document, a raster image (PNG/JPEG) limits quality and editability. Processing can record the vector drawing commands directly into a PDF file, preserving lines, text, and stroke styles at any resolution.

Thesis: Using beginRecord(PDF, "filename.pdf") and endRecord() lets you generate true vector PDFs from a 2D Processing sketch, with a few practical constraints.

How PDF recording works in Processing

Processing’s beginRecord function starts capturing all subsequent drawing commands into a specified file format. When the format is PDF, the output is a PDF vector file. The recording stops when endRecord is called. Everything drawn between these two calls—shapes, text, stroke, fill, and transformations—is stored as PDF primitives.

Worked example: Exporting a simple logo

The following sketch draws a stylized logo consisting of a rectangle, a circle, and some text. It records a single frame into logo.pdf. Place the code in the Processing IDE and run it.

import processing.pdf.*;

void setup() {
  size(400, 400);
  // Start PDF recording on the first frame
  beginRecord(PDF, "logo.pdf");
  noLoop(); // we only need one frame
}

void draw() {
  background(255);
  // Logo elements
  fill(200, 50, 50);
  rect(50, 150, 300, 100, 20);
  fill(50, 150, 200);
  ellipse(200, 200, 120, 120);
  fill(0);
  textAlign(CENTER, CENTER);
  textSize(48);
  text("Proc", 200, 200);
  // Stop recording after drawing this frame
  endRecord();
}

Explanation:

• The PDF library is imported with import processing.pdf.*;.
• beginRecord is called in setup so recording starts immediately.
• noLoop ensures draw runs only once, preventing multiple pages.
• After drawing the logo, endRecord finalizes the PDF.

Verifying the exported PDF

To confirm the output is truly vector:

1. Open logo.pdf in a PDF viewer and zoom in—edges should stay crisp.
2. Open the same file in a vector editor such as Inkscape or Adobe Illustrator.
3. Select the rectangle, circle, or text; you should be able to edit the paths or text properties, confirming that the PDF contains vector primitives, not a raster bitmap.

Trade‑offs and limitations

• Renderer restriction: PDF recording only works with the default 2D renderer. Using P3D or OPENGL will ignore 3D transformations and produce a flat output.
• Font handling: Fonts must be either Processing‑compatible .vlw files or system fonts. Embedded fonts are not subsetted, so using many typefaces can increase file size.
• Color space: Colors are stored in RGB. Direct CMYK profiles are not supported; if you need CMYK for print, you must convert the PDF externally.
• Single‑frame capture: By default each call to beginRecord/endRecord creates one page. Multi‑page PDFs require calling the pair multiple times, typically within a loop that advances to a new page via nextPage() (available in the PDF library).

Actionable next steps

If you need vector output from your Processing sketches:

1. Ensure your sketch uses the default 2D renderer (size(w, h) without P3D or OPENGL).
2. Wrap the drawing you want to capture with beginRecord(PDF, "out.pdf") and endRecord().
3. Run the sketch, inspect the PDF in a viewer, and verify editability in a vector tool.
4. If you require multiple pages or CMYK output, plan for post‑processing with tools like pdftk, Ghostscript, or Adobe Acrobat.

By following this approach you can move from screen‑only sketches to scalable, print‑ready vector files without leaving the Processing environment.