# Flattermarken > Source: https://docs.barcoder.ai/docs/standards/flattermarken > research date 2026-10-03 · extracted at 2026-10-03 > Publisher: Barcoder — encyclopedia of QR, barcode and payment-code standards Specifications: - [Zint Barcode Generator manual — §6.7.2 Flattermarken](https://raw.githubusercontent.com/zint/zint/master/docs/manual.txt) - [Flattermarke — Wikipedia (de)](https://de.wikipedia.org/wiki/Flattermarke) ## Overview Flattermarken (German, singular *Flattermarke*; English *collating marks*, *black steps* or *back marks*) are printed marks on the spine of folded print sheets whose position shifts uniformly from sheet to sheet, so that missing, duplicated or out-of-order sheets can be spotted [6][6][7][7][8][8]. The barcode libraries Zint and bwip-js expose a "Flattermarken" symbology that turns a digit string into such positional marks; Zint's manual stresses that it "is not a true barcode symbol and requires precise knowledge of the position of the mark on the page" [1][1][3][3]. ## History Flattermarken belong to the long tradition of bookbinders' gathering aids. The older practice was the **signature mark** — a letter, number or combination printed at the bottom of the first page of a section so that the binder could order pages and sections correctly; that practice has since been superseded by changes in printing and binding technology and is rarely found in modern books [10][10]. The positional black-step mark is defined in the Etherington & Roberts *Dictionary of Bookbinding and Conservation* as a heavy line about 6 points thick and 24 points long on the back of a folded section [8][8]. No fetched source gives an inventor or a date of origin for the mark, or for its adoption as a named symbology in barcode software. ## Technical specification **The printed mark (bindery practice).** - German Wikipedia describes small black bars, typically **2 × 10 mm**, printed on each folded signature at a progressively greater distance from the top edge; correctly gathered, they form a descending staircase on the spine of the book block [6][6]. The CTAN *collating-marks* module describes the same stair-like pattern: each section's mark is shifted by the length of the rule [9][9]. - The Etherington & Roberts dictionary gives a mark about **6 pt thick × 24 pt long**, appearing as a diagonal line from head to tail across the back of the text block; a missing or misplaced section breaks the line [8][8]. - Imposition software places these marks automatically. KODAK Preps 11 adds collation marks "to identify the planned sequence of the sections in a product assembly, based on the binding style", with settable width, length and step distance, and several mark styles including numeric indicators [11][11]. **The barcode-library symbology.** - **Character set:** digits 0–9 only [1][1][4][4]. - **Check digit:** none [1][1][4][4][5][5]. - **Length:** Zint's current manual limits input to **128 digits**, and its encoder rejects longer input [1][1][2][2]. bwip-js 4.11.0 allows up to **500 characters** [3][3]. The DataFlex and symbology.dev references say "any length" [4][4][5][5]. - **Encoding (as implemented):** each digit takes a 9-module cell. Digits 1–9 place one module-wide bar at position *n* in the cell, and **0 leaves the cell blank**. Zint's table maps `1` → `18` (bar 1, space 8), `2` → `0117`, … `9` → `0810`, and `0` → `0504` (spaces only) [2][2]. bwip-js uses the equivalent table `0018`, `0117` … `0810`, `0900` for 1…9, 0 [3][3]. Rendering the sample `11099` with bwip-js gives a 45-module-wide symbol with marks in cells 1, 2, 4 and 5 and an empty third cell. An input of just `0` draws nothing. - **Dimensions:** Zint's source has a `TODO: Find documentation on BARCODE_FLAT dimensions/height` comment, so it follows no published dimensional specification [2][2]. Zint assigns the symbology ID **28 (`BARCODE_FLAT`)** [1][1]. ## Use cases - **Book production / bindery collation:** checking that folded signatures are complete and gathered in the right order (*Kollationieren*) [6][6][8][8][9][9]. - **Packaging:** marks on the edges of folded cartons form continuous lines when stacked. A break shows that cartons from a different print version have been mixed in, which keeps obsolete artwork out of production. Wikipedia says the international term here is "identification mark" [6][6]. - **Passports / security documents:** Reconnaissance International's glossary describes the collation mark in passports as an added safeguard that makes swapped or removed pages easier to detect [12][12]. - **Prepress imposition:** KODAK Preps generates collation marks automatically, including for jobs that mix binding styles [11][11]. ## Implementations - **[zint](https://github.com/zint/zint)**: C, ~810 stars, active October 2026. `zint_flat()` in `backend/postal.c` is an encoder (symbology `BARCODE_FLAT`, CLI `-b FLAT`), limited to 128 digits [1][1][2][2]. - **[bwip-js](https://github.com/metafloor/bwip-js)**: JavaScript, ~2.4k stars, active August 2026. Lists `flattermarken` among its symbologies (`bcid: "flattermarken"`) and implements it as `bwipp_flattermarken`, which allows up to 500 digits [3][3]. - **CTAN `collating-marks`** (ConTeXt/MetaPost, public domain, by W. Egger) draws collating marks while arranging pages for folding into sections [9][9]. No decoder library was found. Because the mark is read by its position on the page rather than scanned as a bar/space sequence, a general-purpose barcode decoder has nothing to decode [1][1]. ## Comparison - **Flattermarken vs. signature marks:** traditional signature marks are characters (letters/numbers) printed on the first page of each section and have to be read one by one. A Flattermark is a position-coded bar, and a misplaced section shows up at a glance as a break in the diagonal across the spine [8][8][10][10]. Signature marks have largely fallen out of use, while collation marks are still generated by current imposition software [10][10][11][11]. - **Flattermarken vs. [FIM](https://docs.barcoder.ai/docs/standards/fim):** Zint's manual puts both in the same chapter, "Other Barcode-Like Markings" (§6.7.1 FIM, §6.7.2 Flattermarken). Both are fixed marks whose meaning depends on where they sit on the item rather than on general-purpose symbol data [1][1]. FIM uses a small set of fixed patterns, while Flattermarken take arbitrary digit strings [1][1]. ## Fun facts - Zint's source code introduces the encoder with the comment "Flattermarken - Not really a barcode symbology!", and still notes that it has no documentation for the mark's dimensions [2][2]. - The German name comes from bookbinding vocabulary. Duden lists *Flattermarke* as a printing-trade term for a mark on the spine of every folded sheet "whose position changes uniformly" [7][7]. ## Status **Active as a print-production practice, niche as a barcode symbology.** Collation marks are still a standard feature of current imposition software (KODAK Preps 11) [11][11]. The digit-encoding symbology is maintained in Zint (commits in 2026) and bwip-js (4.11.x) [1][1][2][2][3][3]. No standards body has published a formal specification. The implementations disagree on maximum length, and Zint's source admits that no dimension documentation exists [2][2][3][3]. No successor exists. ## Sources [1] [Zint Barcode Generator and Zint Barcode Studio User Manual (§6.7.2 Flattermarken; symbology table)](https://raw.githubusercontent.com/zint/zint/master/docs/manual.txt) — Robin Stuart / zint project, accessed 2026. [2] [zint `backend/postal.c` — `zint_flat()`](https://raw.githubusercontent.com/zint/zint/master/backend/postal.c) — GitHub (zint/zint), accessed 2026. [3] [bwip-js — Barcode Writer in Pure JavaScript](https://github.com/metafloor/bwip-js) (README symbology list via [jsDelivr](https://cdn.jsdelivr.net/npm/bwip-js@4.11.4/README.md); `bwipp_flattermarken` source in npm package 4.11.0) — metafloor, accessed 2026. [4] [Flattermarken](https://docs.dataflex.dev/reports/explanations/barcode-types/flattermarken/) — DataFlex Reports documentation, accessed 2026. [5] [Other Barcode-Like Markings](https://symbology.dev/reference/other) — symbology.dev, accessed 2026. [6] [Flattermarke](https://de.wikipedia.org/wiki/Flattermarke) — Wikipedia (German), accessed 2026. [7] [Flattermarke](https://www.duden.de/rechtschreibung/Flattermarke) — Duden, accessed 2026. [8] [Black step — Bookbinding and the Conservation of Books: A Dictionary of Descriptive Terminology](https://cool.culturalheritage.org/don/dt/dt0337.html) — Etherington & Roberts, via CoOL / AIC, accessed 2026. [9] [Module: Collating Marks (README)](https://softlibre.unizar.es/ctan/macros/context/contrib/context-collating-marks/README.md) — CTAN mirror, W. Egger, accessed 2026. [10] [Signature mark](https://en.wikipedia.org/wiki/Signature_mark) — Wikipedia, accessed 2026. [11] [Collation marks — KODAK Preps 11](https://workflowhelp.kodak.com/x/ORLTE) — Kodak Workflow Help, accessed 2026. [12] [Collation mark](https://prod.reconnaissance.net/glossary/collation-mark/) — Reconnaissance International glossary, accessed 2026. [1]: https://raw.githubusercontent.com/zint/zint/master/docs/manual.txt [2]: https://raw.githubusercontent.com/zint/zint/master/backend/postal.c [3]: https://github.com/metafloor/bwip-js [4]: https://docs.dataflex.dev/reports/explanations/barcode-types/flattermarken/ [5]: https://symbology.dev/reference/other [6]: https://de.wikipedia.org/wiki/Flattermarke [7]: https://www.duden.de/rechtschreibung/Flattermarke [8]: https://cool.culturalheritage.org/don/dt/dt0337.html [9]: https://softlibre.unizar.es/ctan/macros/context/contrib/context-collating-marks/README.md [10]: https://en.wikipedia.org/wiki/Signature_mark [11]: https://workflowhelp.kodak.com/x/ORLTE [12]: https://prod.reconnaissance.net/glossary/collation-mark/ ## Deployments _No country reports mention this standard by name._ ## Regions / aggregations not mapped to a single country - Universal