# Printable Flashcards (Double-sided PDF)

> Print flashcards on both sides: questions on the front, answers exactly behind them, as a PDF. Lays out flashcards on card or label sheets (business-card size 90 × 54 mm, 99 × 68 mm, 70 × 37 mm and US Letter 4 × 2 in, among others): questions on the front pages, answers on the back pages mirrored for long-edge or short-edge duplex printing, cut lines, registration crosses and a card number on both sides. Text shrinks to fit (down to 6 pt). Also prints questions only, or question and answer side by side for folding. Vector PDF with embedded fonts for Latin, Greek, Cyrillic, Arabic, Devanagari, Chinese, Japanese and Korean.

Part of usefulweb.site (https://usefulweb.site/). Part of [Deckwright](https://deckwright.usefulweb.site/) (ownerApp: deckwright). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://deckwrightprintcards.usefulweb.site/ (interactive tool at https://deckwrightprintcards.usefulweb.site/tool)
- JSON API: POST https://deckwrightprintcards.usefulweb.site/api/v1/calculate with a JSON object of inputs (schema: https://deckwrightprintcards.usefulweb.site/api/v1/tool)
- OpenAPI: https://deckwrightprintcards.usefulweb.site/openapi.json
- MCP (Streamable HTTP): https://deckwrightprintcards.usefulweb.site/mcp - tool `deckwright_print_cards`

## Inputs
- text (textarea): Cards - Markdown: “Q:” and “A:” lines, “term :: definition” (“:::” also makes the reverse card), {{c1::cloze}} gaps, # headings as tags. Or CSV/TSV rows (front, back, tag), an Anki plain-text export, or a slide deck.
- format (select): Format
- reverse (boolean): Also make reverse cards (answer → question)
- sheet (select): Card sheet
- sides (select): Sides
- flip (select): Duplex flip edge
- cutLines (boolean): Cut lines around the cards
- sizePt (number): Largest text size
- lang (text): Card language (BCP 47, e.g. en, es, ja) - Used for answer checks and fonts; empty = English.

## Method
- Sheet geometry (paper, columns × rows, card size, margins, pitch) comes from Printshop’s label sheets. Fronts are on odd pages, backs on even pages. For a long-edge flip the back of the card in column c sits in column (columns − 1 − c), x′ = page width − x − card width; for a short-edge flip the rows are mirrored, y′ = page height − y − card height.
- Text is shaped with embedded Noto fonts and wrapped like slide text (Chinese, Japanese and Korean by characters); it starts at the chosen size and shrinks in 8 % steps down to 6 pt. Cards that still do not fit are cut and listed. Pictures (data URLs) are placed above the text.
- Reverse cards are not printed separately: a printed card already has the answer on its back.
- Registration crosses sit 7 mm from each page corner on both sides; hold a printed sheet against the light to check that the printer keeps front and back aligned. Every card carries its number on both sides.

## Limits
- Printers shift the back side by up to a few millimetres; print one test sheet on plain paper first. Choose “actual size” (100 %) in the print dialog.