Single Line Fonts for Pen Plotters
Pen plotters are the original single-line font machines. Whether you're using a modern AxiDraw or a vintage HP 7475A, the same principles apply: minimize pen lifts, maximize stroke continuity, and choose fonts designed for physical pen output.
Why pen plotters need SLF fonts
When a pen plotter draws a letter from a standard TTF font, it traces both edges of each stroke — the same double-outline problem as laser engravers. The result looks like a hollow letter, not natural handwriting. Single line fonts produce a single pen stroke per letter, which is what plotters were designed to do. The AxiDraw in particular is often used for handwriting simulation — and nothing simulates handwriting better than a font designed as a single stroke.
Travel distance: the dominant factor for plotters
Unlike laser engravers (where speed is fast enough that travel time is a minor factor), pen plotters are slow enough that travel distance dominates total plot time. A typical unoptimized A4 text layout can have 5–10 minutes of pen-up travel. Pathhaus's Travel Optimizer, which reorders strokes to minimize pen-up movement, typically reduces this to 1–3 minutes. For long documents or production plotting, this is the single most impactful optimization you can make.
Choosing the right pen
Pen choice affects how font quality is perceived. Fine-tip pens (0.3–0.5mm) expose every slight path imperfection — they benefit most from Pathhaus optimization. Broader brush pens (1–2mm) are more forgiving but require fonts with consistent stroke weight. For AxiDraw: Staedtler Triplus 0.3mm, Micron 0.3mm, and Pentel Sign 1.0mm are community favorites. Ballpoint pens require slightly higher servo pressure settings and produce a slightly different line quality.
HPGL vs SVG for plotters
Most modern pen plotters accept SVG, but vintage machines like the HP 7475A and Roland plotters speak native HPGL. Pathhaus exports HPGL directly (Pro feature) — no conversion needed. HPGL files are typically 40–60% smaller than equivalent SVGs and process faster on older controllers. If you're using an AxiDraw with Inkscape, use SVG. For any vintage HP or Roland plotter, use Pathhaus's HPGL export.
Try it in Pathhaus Studio
Free to start — optimize and export your first font file in under 5 minutes.