fontstack 0.1.3

Unicode text rendering with automatic per-character font fallback, BiDi support, and emoji

FontStack

Unicode text rendering for Pillow with automatic per-character font fallback, variable fonts, BiDi/RTL, and emoji.

Pillow's built-in text rendering uses a single font, so any character not covered by that font shows up as a blank box ("tofu"). FontStack fixes this by walking an ordered list of fonts per character, the same fallback strategy browsers and operating systems use. It also handles right-to-left scripts, Arabic contextual shaping, variable fonts, TrueType Collections, and emoji.

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Features

• Per-character font fallback using fonttools for accurate cmap parsing across TTF, OTF, and collection formats.
• RTL/BiDi support via python-bidi for Unicode BiDi reordering. Arabic text is reshaped with arabic-reshaper before rendering so letters connect correctly under Pillow's BASIC layout engine.
• Emoji rendered via Pilmoji / Twemoji with correct baseline alignment across mixed font and emoji runs.
• Variable font support: set axes by integer value (weight=700 sets wght) or by named style (weight="Bold"). Typed VariationAxes for IDE autocomplete on standard axes.
• TrueType/OpenType Collection support (.ttc / .otc) via ttc_index on FontConfig.
• Two rendering modes: "wrap" breaks text across lines at a max width; "scale" shrinks the font to fit, truncating with … as a last resort.
• Fit mode ("fit") combines both: wraps at max_width, then shrinks the font until the block fits within max_height, then truncates the last visible line with … if necessary. min_size sets the floor for both scale and fit modes.
• Left, center, and right alignment within the text block.
• LRU caching on both font objects and cmap data; repeated renders with the same stack/size/weight are essentially free.
• Fully typed: Literal on mode and align, @overload signatures that surface min_size only when mode="scale" or mode="fit" and max_height only when mode="fit", PEP 561 py.typed marker.

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Gallery

Nine languages, one stack	Chinese · Japanese · Korean
Devanagari · Hebrew · Bengali · Thai	Variable font weight axis (wght 100–900)
Mixed Arabic + Latin - BiDi reordering applied automatically
Symbols · Math alphanumerics · Box drawing · Arrows
Fit mode - wrap → shrink → truncate, all four strips share the same bounding box

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Installation

pip install fontstack

Note: FontStack does not bundle fonts. See Recommended Font Stack below for a curated set of free Noto fonts that provide near-complete Unicode coverage.

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Quick Start

from fontstack import FontConfig, FontManager

manager = FontManager(
    default_stack=[
        FontConfig(path="fonts/NotoSans[wdth,wght].ttf"),
        FontConfig(path="fonts/NotoSansArabic[wdth,wght].ttf"),
    ]
)

from PIL import Image

img = Image.new("RGBA", (800, 100), "white")
manager.draw_text_smart(
    image=img,
    text="Hello مرحبا",
    position=(20, 20),
    size=48,
    weight=700,
    fill=(20, 20, 20),
)
img.save("output.png")

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Usage

FontManager

from fontstack import FontConfig, FontManager, VariationAxes

manager = FontManager(
    default_stack=[
        # Primary font: Noto Sans variable (Latin, Cyrillic, Greek)
        FontConfig(path="fonts/NotoSans[wdth,wght].ttf"),
        # Fallback 1: Noto Sans Arabic (Arabic, Persian, Urdu)
        FontConfig(path="fonts/NotoSansArabic[wdth,wght].ttf"),
        # Fallback 2: Noto Sans SC/JP/KR (Simplified Chinese / Japanese / Korean)
        FontConfig(path="fonts/NotoSansSC[wght].ttf"),
        FontConfig(path="fonts/NotoSansJP[wght].ttf"),
        FontConfig(path="fonts/NotoSansKR[wght].ttf"),
    ]
)

from PIL import Image

img = Image.new("RGBA", (1000, 200), "white")
w, h = manager.draw_text_smart(
    image=img,
    text="Hello 世界 مرحبا 🌍",
    position=(20, 40),
    size=48,
    weight=700,
    mode="wrap",
    max_width=960,
    align="center",
    fill=(30, 30, 30),
)
print(f"Rendered {w}×{h} px")
img.save("output.png")

render_text

Returns a new PIL.Image.Image cropped tightly to the rendered text, no canvas management needed.

from fontstack import FontConfig, render_text

img = render_text(
    text="Hello 世界 مرحبا 🌍",
    font_stack=[
        FontConfig(path="fonts/NotoSans[wdth,wght].ttf"),
        FontConfig(path="fonts/NotoSansArabic[wdth,wght].ttf"),
    ],
    size=48,
    weight=700,
    fill=(20, 20, 20),
    background="white",
    padding=16,
)
img.save("hello.png")

Variable font axes

from fontstack import FontConfig, VariationAxes

# Narrow, light weight, slightly slanted
FontConfig(
    path="fonts/NotoSans[wdth,wght].ttf",
    axes=VariationAxes(wght=300.0, wdth=75.0, slnt=-10.0),
)

Standard axes in VariationAxes: wght (weight, 100–900), wdth (width, 50–200), ital (italic, 0–1), slnt (slant, degrees), opsz (optical size).

Rendering modes

# "wrap" - word-wrap at max_width, font size unchanged
manager.draw_text_smart(img, long_text, position=(0, 0), size=32,
                        mode="wrap", max_width=400)

# "scale" - shrink font until the full text fits on a single line;
#             truncates with "…" if the text is still too wide at min_size
manager.draw_text_smart(img, long_text, position=(0, 0), size=32,
                        mode="scale", max_width=400, min_size=10)

# "fit" - wrap first, then shrink until the block fits within max_width × max_height;
#           if the block still overflows at min_size the last visible line is
#           truncated with "…"
manager.draw_text_smart(img, long_text, position=(0, 0), size=32,
                        mode="fit", max_width=400, max_height=120, min_size=10)

Batch rendering with a shared manager

Reusing a FontManager across many render_text calls avoids re-parsing cmaps for every image.

from fontstack import FontConfig, FontManager, render_text

mgr = FontManager(default_stack=[FontConfig(path="fonts/NotoSans[wdth,wght].ttf")])

labels = ["First", "Second", "Third", ...]
images = [render_text(label, font_stack=[], manager=mgr, size=32) for label in labels]

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Recommended Font Stack

All fonts below are from Google's Noto family, licensed under the SIL Open Font License 1.1 (free for commercial use).

#	Font	Scripts covered	Size	Download
1	Noto Sans [wdth,wght].ttf	Latin, Cyrillic, Greek, Latin Extended	~1.1 MB	Google Fonts
2	Noto Sans Arabic [wdth,wght].ttf	Arabic, Persian, Urdu	~840 KB	Google Fonts
3	Noto Sans SC [wght].ttf	Simplified Chinese	~17 MB	Google Fonts
4	Noto Sans JP [wght].ttf	Japanese	~9.4 MB	Google Fonts
5	Noto Sans KR [wght].ttf	Korean	~10 MB	Google Fonts
6	Noto Sans Devanagari [wdth,wght].ttf	Hindi, Sanskrit, Marathi, Nepali	~632 KB	Google Fonts
7	Noto Sans Hebrew [wdth,wght].ttf	Hebrew, Yiddish	~110 KB	Google Fonts
8	Noto Sans Bengali [wdth,wght].ttf	Bengali, Assamese	~454 KB	Google Fonts
9	Noto Sans Thai [wdth,wght].ttf	Thai	~214 KB	Google Fonts

Emoji are handled by Pilmoji/Twemoji automatically, no emoji font needed in the stack.

from fontstack import FontConfig, FontManager

FONT_DIR = "fonts"

manager = FontManager(
    default_stack=[
        FontConfig(path=f"{FONT_DIR}/NotoSans[wdth,wght].ttf"),
        FontConfig(path=f"{FONT_DIR}/NotoSansArabic[wdth,wght].ttf"),
        FontConfig(path=f"{FONT_DIR}/NotoSansSC[wght].ttf"),
        FontConfig(path=f"{FONT_DIR}/NotoSansJP[wght].ttf"),
        FontConfig(path=f"{FONT_DIR}/NotoSansKR[wght].ttf"),
        FontConfig(path=f"{FONT_DIR}/NotoSansDevanagari[wdth,wght].ttf"),
        FontConfig(path=f"{FONT_DIR}/NotoSansHebrew[wdth,wght].ttf"),
        FontConfig(path=f"{FONT_DIR}/NotoSansBengali[wdth,wght].ttf"),
        FontConfig(path=f"{FONT_DIR}/NotoSansThai[wdth,wght].ttf"),
    ]
)

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API Reference

FontManager(default_stack, max_cache=30)

Method	Returns	Description
draw_text_smart(image, text, position, ...)	tuple[int, int]	Draw text onto an existing image in-place. Returns (width, height) of the rendered bounding box.
get_font_chain(size, weight, custom_stack)	list[FreeTypeFont]	Return loaded font objects for the given size/weight (LRU-cached).
default_stack	list[FontConfig]	Read-only copy of the stack passed at construction.

draw_text_smart key parameters

Parameter	Type	Default	Description
size	int	40	Starting font size in points.
weight	int | str	400	Font weight axis value or named style string (e.g. 700 or "Bold").
mode	"wrap" | "scale" | "fit"	"wrap"	Rendering mode.
max_width	int | None	None	Maximum line width in pixels.
max_height	int | None	None	Maximum block height in pixels ("fit" mode only).
min_size	int	12	Minimum font size for "scale" and "fit" modes.
align	"left" | "center" | "right"	"left"	Horizontal alignment within the text block.
line_spacing	float	1.2	Line-height multiplier (1.0 = tight, 1.5 = loose).
fill	FillType	"black"	Text color: color name, RGB/RGBA tuple, or palette integer.
font_stack	list[FontConfig] | None	None	Per-call font stack override; falls back to default_stack.
emoji_source	BaseSource	Twemoji	Pilmoji emoji image source.

render_text(text, font_stack, ...) -> Image.Image

Convenience wrapper: creates a FontManager (or reuses one via manager=), renders text, and returns a new RGBA image cropped to the result with optional padding and background.

FontConfig

Field	Type	Default	Description
path	str	required	Path to TTF, OTF, TTC, or OTC file.
axes	VariationAxes | None	None	Default variable font axis values.
ttc_index	int	0	Index within a TTC/OTC collection.

VariationAxes (TypedDict, all optional)

wght · wdth · ital · slnt · opsz

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Requirements

• Python 3.11+
• Pillow ≥ 12.2
• pilmoji ≥ 2.0.5
• fonttools ≥ 4.62
• python-bidi ≥ 0.6.7
• arabic-reshaper ≥ 3.0.0

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License

MIT © 2026 Kanin