About

Handwriting synthesis requires controlled stochastic variation across multiple parameters: baseline offset (dy), character rotation (θ), letter spacing (Δx), and stroke opacity (α). Without proper jitter distribution, output looks mechanical and fails to pass visual inspection. This tool renders each glyph individually on an HTML Canvas element, applying per-character randomness drawn from configurable ranges. It produces downloadable PNG images on real ruled-paper backgrounds. The algorithm handles word-wrapping, paragraph breaks, and page margins. Results approximate natural ballpoint or fountain pen output. Note: this tool uses font-based glyph shapes with positional perturbation. It does not simulate pressure-sensitive stroke dynamics or connected cursive ligatures beyond what the chosen style provides.

Formulas

Each character at index i is placed at position (x_i, y_i) with transformations applied before rendering:

x_i = x_i−1 + charWidth(c_i−1) + Δx + rand(−1, 1)

y_i = y_base + rand(−dy, dy)

θ_i = φ + rand(−θ_max, θ_max)

s_i = s + rand(−Δs, Δs)

α_i = clamp(α + rand(−Δα, Δα), 0, 1)

Where c_i is the character at position i, rand(a, b) returns a uniform random value in [a, b], φ is the global slant angle in radians, and clamp restricts the value to the valid range. Line wrapping occurs when x_i + charWidth(c_i) > W − m_R, at which point x resets to m_L and y_base increments by h.

Reference Data

Parameter	Symbol	Default	Range	Effect
Font Size	s	18px	12 - 32px	Glyph height on paper
Line Spacing	h	32px	24 - 56px	Vertical distance between baselines
Letter Spacing	Δx	0px	−3 - 5px	Horizontal gap between glyphs
Baseline Jitter	dy	1.5px	0 - 4px	Random vertical offset per character
Rotation Jitter	θ	0.02rad	0 - 0.08rad	Random tilt per character
Size Jitter	Δs	0.5px	0 - 3px	Random font size variation
Global Slant	φ	0°	−15 - 15°	Consistent italic lean
Ink Opacity	α	0.85	0.4 - 1.0	Stroke transparency
Opacity Jitter	Δα	0.08	0 - 0.25	Simulates ink flow variation
Word Spacing	w	6px	3 - 15px	Gap width at space characters
Left Margin	m_L	80px	40 - 140px	Red margin line position
Top Margin	m_T	60px	30 - 100px	First baseline offset from top
Paper Width	W	816px	Fixed (Letter/A4)	Canvas horizontal resolution
Paper Height	H	1056px	Dynamic (grows with text)	Canvas vertical resolution

Frequently Asked Questions

Characters near the right margin undergo word-wrap checks based on measured glyph width. If your font size is large and letter spacing is high, the last character before a wrap may extend slightly beyond the margin. Reduce font size or letter spacing to mitigate this. The algorithm uses a right margin buffer equal to the left margin value.

Baseline jitter (dy) shifts each character vertically from the ruled line, simulating unsteady hand movement along the Y-axis. Rotation jitter (θ) tilts the character around its center point. Both are independent random variables. High baseline jitter with zero rotation produces wavy but upright text. High rotation with zero baseline jitter produces tilted but line-aligned text. Combining both yields the most natural result.

Yes. The canvas height grows dynamically based on text length. When text exceeds one page height (1056px for Letter size), the canvas extends. The download will be a single tall image. For physical printing, your print dialog will split it across pages. The ruled lines and margins continue seamlessly across the extended canvas.

Small jitter values (below 0.5px for baseline, below 0.01 rad for rotation) produce imperceptible variation. Natural handwriting typically exhibits baseline jitter of 1-2px and rotation jitter of 0.02-0.04 rad at 18px font size. Use the "Messy" preset for aggressive randomness, or manually increase jitter values. Also check that opacity jitter is non-zero, as consistent ink density is a strong mechanical cue.

The canvas renders at 1:1 pixel ratio by default (816×1056 for US Letter). For higher resolution output, increase the paper size or use browser zoom before downloading. The PNG export captures the exact canvas pixels. At default settings, output is 96 DPI equivalent. For 150 DPI print quality, the current dimensions are sufficient for a 5.4×7 inch print area.

The tool renders each character independently with per-glyph transforms. It does not generate connecting strokes between letters. The available handwriting styles use pre-designed font faces that may include cursive-style letterforms, but ligatures and inter-letter connections are visual properties of the font itself, not dynamically generated paths. For connected script appearance, select a cursive-style handwriting font from the style options.