AI — Adobe Illustrator Format: What It Is, Exporting OSM Maps for Designers

AI is the native vector format of Adobe Illustrator, alive since 1987. A modern .ai file is under the hood a PDF document with extra Illustrator-specific metadata, packaged in a way Illustrator recognizes as its own. This dual nature has a practical consequence: an AI file opens in any PDF viewer (it'll show contents), but for editing layers, text blocks, and styles you need Illustrator itself or its direct heirs. On osm2cdr.ru AI export works by generating PDF that Illustrator opens as a native document — all layers, fonts, colors preserved.

History: from PostScript heir to PDF wrapper

Adobe Illustrator shipped on March 19, 1987 for Macintosh — one of the first vector design programs on mass-market computers. Version 1.0 stored documents in a format that was technically extended EPS (Encapsulated PostScript): ASCII PostScript code plus DSC comments for metadata and a preview image for the Finder.

This EPS basis held until Illustrator 8.0 in 1998. Each major version (Illustrator 88, 3, 5, 7, 8) extended the PostScript operator set with its own pdfAI comments: new fill types, gradients, filters, layers (absent in standard PostScript). Compatibility between versions was weak: an AI file from Illustrator 7 wouldn't open lossless in 5, and vice versa.

In 2000 Adobe shipped Illustrator 9.0 — an architecture revolution. The AI format moved from PostScript to PDF as its base. Technically the file started with the PDF header %PDF-1.4 %âãÏÓ, and any PDF viewer would recognize it as a regular document. But Adobe added private dictionary objects tagged AIPrivateData (or PGF — Plate Generation Format for short) — native Illustrator blocks describing program-specific features: live effects, mesh gradients, brushes, symbols. Third-party PDF readers simply ignore this data, displaying a "flat" version.

From 2000 to today's Illustrator 2024 (version 28), the format stays PDF-based. Adobe changes major numbers as marketing identifiers (CC 2014 = 18, CC 2015 = 19, …, 2024 = 28), but base compatibility holds — Illustrator 2024 opens AI from Illustrator 9.

What's inside a modern AI file

A hexdump of the first 16 bytes of a typical .ai:

00000000  25 50 44 46 2d 31 2e 36  20 25 e2 e3 cf d3 0a 25
          %  P  D  F  -  1  .  6  ␣  %  â  ã  Ï  Ó  \n  %

Standard PDF header version 1.6. Next — usual PDF structure: cross-reference table, object dictionary, content streams, trailer. Content streams hold Adobe Imaging Model vector operators — lines, curves, fills.

Illustrator-specific data lives in separate PDF objects with metadata like /AIPrivateData true. These objects contain binary serialization of internal Illustrator structures: layer drawing path, active guides, snapping settings. Third-party programs skip them, but the embedded flat PDF content is complete — a map stays a map even without AI specifics.

The PDF wrapper's advantage is obvious: an AI file opens in Preview on Mac, Acrobat, Foxit, and even in a browser (Chrome shows PDF inline). For "designer in Illustrator, typesetter views without Adobe" collaboration this matters.

Who needs AI

Poster or book cover designer. Main audience. A Paris district map becomes a poster background — the designer opens AI in Illustrator, recolors roads to brand palette, adds typography, exports to PDF/X for print. 15–30 minute workflow.

Magazine illustrator. Thematic map for an article: tour preview, event retrospective, election analytics. The illustrator takes the AI map, draws over with arrows, annotations, icons, saves AI for the editor and exports PDF for print.

Cartographer freelancer. Takes orders for coloured cartography — maps for wedding invitations, startup infographics, historical research. AI is the main tool: each building or road category on its own layer, easy recolor, add text, export to any target format.

Branding studio. Office company map for onboarding materials, district map for real estate marketing. The studio opens an AI map, applies the brand book (colors, fonts, icons), saves AI as a master file for future updates.

AI-reading software

Adobe Illustrator. Paid, Creative Cloud subscription ~23 USD/mo (or single Illustrator plan). Windows, macOS, iPad. The format's reference. Version 2024 (28) is current stable. adobe.com/products/illustrator

Affinity Designer. Paid, one-time around 70 USD, no subscription. Windows, macOS, iPad. UK Serif. Opens AI via PDF parser with high accuracy: layers, text, gradients — all there. Doesn't open Illustrator-specific effects (live distort, mesh tools). affinity.serif.com/designer

Inkscape. Free, GPL, cross-platform. Opens AI 8 and older via legacy PostScript parser. For AI 9+ (PDF-based) — via PDF import: File → Import → pick .ai. Styles partially lost, geometry preserved. inkscape.org

CorelDRAW. Paid, around 269 USD/year. Windows, macOS (since 2019, reduced functionality). Imports AI via File → Import, converts to CDR. Often used in Eastern European print shops for final prep.

Any PDF viewer. Adobe Reader, Foxit, Preview (macOS), browsers Chrome/Edge — all open AI as a regular PDF and show the "flat" version. Not editable, but ideal for preview.

Sketch (macOS). Paid, around 99 USD/year. UI design tool. AI import limited — simple geometry reads, complex effects lost.

Pros and cons

Pros. Industry standard in design and print. Deep Creative Cloud integration (Photoshop, InDesign, After Effects). Preserves Pantone spot colors, CMYK, layers, text styles. Opens in any PDF viewer for preview. Infinite vector scaling. Backward compatibility to 2000.

Cons. Proprietary — full-fidelity edit only in Illustrator. Paid subscription (~280 USD/year for commercial use). Vendor lock-in: AI-specific effects (mesh gradients, live effects) lost on SVG/PDF export. Alternatives (Inkscape, Affinity) work but with losses. iPad Illustrator isn't ideal — large AI files lag.

AI vs SVG vs PDF vs EPS

AI — for design in the Illustrator ecosystem. SVG — for web and editing in design tools. PDF — for universal print and delivery. EPS — for legacy print shops requiring PostScript. Detailed comparison in the AI and EPS article.

How to make an AI map from OpenStreetMap

Step 1. On osm2cdr.ru pick AI from the format dropdown. Vector category.

Step 2. Draw the area. For an A2 poster (420×594 mm) — 1–3 km. For book illustration — 0.5–1 km. For office district branding — 0.3–0.8 km.

Step 3. Style. standard keeps OSM colors as a starting point — the designer recolors anyway. minimal gives a muted start for brand recoloring. monochrome if you plan a background under bright typography.

Step 4. DPI. For AI usually not critical (vector scales), but if there are raster elements — 300 for print. Document size (width mm) — set by target medium: 420 mm for A2, 297 mm for A3.

Step 5. Layers. Keep them all — separating buildings/roads/water/green is more convenient than merging. Each OSM layer lands in Illustrator's Layers panel.

Step 6. Click Export. Within 30–90 seconds get the .ai file (technically PDF Illustrator recognizes). Open via File → Open in Illustrator — all layers in place.

Get an AI Map of Paris in 60 Seconds

Pitfalls

Spot colors don't transfer. AI supports Pantone and other spot systems, but our export writes CMYK approximations via QGIS PDF export. If exact Pantone is needed for print — the designer must manually create a swatch in Illustrator and replace.

Fonts embed vs path. By default we embed TTF/OTF fonts in AI. Fine for most Adobe Fonts. For commercial licensed fonts — verify the print shop's policy (some require outlined text, not embed).

Inkscape opens with losses. If the recipient uses Inkscape instead of Illustrator — they'll open AI via PDF parser but lose Illustrator specifics. For guarantees, better export SVG, not AI.

Large files lag. A Moscow center map on A0 (1500×1500 mm) with building detail can hit 50–80 MB AI. Illustrator opens it, but edit operations slow. Solution: reduce our detail level, or work with separate layers.

FAQ

Is Illustrator mandatory? No: any PDF viewer opens AI for viewing; for editing with reasonable feature preservation — Affinity Designer (paid, no subscription) or Inkscape (free).

How is AI different from PDF? Technically a modern AI is PDF plus Illustrator-specific private data. Any PDF viewer shows AI as a regular document. Only Illustrator understands specific effects and layers natively.

Does AI open in Affinity Designer? Yes, via PDF parser. Most features preserved: layers, text, basic gradients. Illustrator-exclusive effects (live distort, mesh gradients) lost.

Does AI work on iPad? Yes, Illustrator iPad is a full-featured Adobe product (separate subscription). Affinity Designer on iPad is an alternative. For viewing — any PDF reader.

Can I batch-process AI? Via Adobe Script (JavaScript for Illustrator) — yes. Via Python libraries — partially: you can read AI as PDF and manipulate PDF objects, but Illustrator-specific effects are inaccessible.

Related

• AI and EPS — maps for Adobe Illustrator
• SVG — W3C open web standard
• Map export for printing: PDF, EPS, AI
• SVG maps for design: Inkscape and Illustrator
• AI format landing

Sources

• Adobe Illustrator File Format Specification — adobe.com/devnet/illustrator
• Wikipedia, Adobe Illustrator Artwork — en.wikipedia.org/wiki/Adobe_Illustrator_Artwork
• Library of Congress, Adobe Illustrator File Formats — loc.gov/preservation/digital/formats/fdd/fdd000356.shtml
• PDF Reference (ISO 32000-1:2008) — pdfa.org/resource/iso-32000-pdf