Labelling Fish Boxes and Crates at Sea

What a fish box label must show

A fish box label must identify the lot and carry the information the next buyer needs to meet traceability and consumer information rules: species, production method, catch area, gear category, net weight, dates and the responsible operator. Exactly which items must be physically printed on the box, and which may travel in commercial documents, depends on whether the box is a trade unit for another food business or a prepack intended for the final consumer.

The table below maps common label items to their EU legal basis. It is a guide for designing label templates, not legal advice for a specific product.

For prepacked food sold to another business before it reaches the final consumer, or supplied to mass caterers, Regulation (EU) No 1169/2011, Article 8(7), allows the mandatory particulars to appear in accompanying commercial documents, but the name of the food, the date marking, storage conditions and the operator's name must still appear on the external packaging. The consumer information items come from Article 35 of Regulation (EU) No 1379/2013. Fish is an allergen listed in Annex II of Regulation 1169/2011, but a separate allergen statement is not required where the name of the food clearly refers to it (Article 21(1)).

The data behind these items is captured during catch registration; see Catch Registration and Traceability from Haul to Harbour.

Barcodes and GS1 identifiers

A GS1 barcode lets the next operator scan a box and capture product, weight, lot and dates without retyping, which is why GS1-128 and GS1 DataMatrix symbols are widely used on fish cases and pallets. The data is encoded as element strings: a GS1 Application Identifier (AI) followed by its value.

Formats from the GS1 Application Identifiers reference. The fishery AIs 7005–7010 must be used together with a GTIN or with the identification of logistic unit contents. A variable-weight box of fish typically combines (01), (3103) and (10), plus a date. Article 39(2) of Regulation 1379/2013 also allows a QR code to carry part or all of the mandatory consumer information, in addition to, not instead of, the printed text.

Practical rules for scannable labels

• Put fixed-length AIs such as (01), (3103) and (15) first and variable-length AIs such as (10) last, so no separator character is needed after them.
• Keep the full quiet zone clear on both sides of a linear barcode; a label edge or a strap across the code causes read failures.
• Print the human-readable interpretation with the AIs in brackets under the bars, so the data can be keyed in if a code is damaged.
• Verify barcodes with a scanner at the start of every trip and after changing label stock or ribbon.

Thermal printers and labels in wet, cold conditions

On a fish deck, thermal transfer printing on synthetic labels with a freezer-grade adhesive is the robust choice; direct thermal paper labels suit short-lived, dry applications. The difference matters because a label that fades, smears or falls off makes the lot untraceable.

Direct thermal printing uses heat-sensitive media that darkens under the printhead; according to Zebra's technical FAQ, it is sensitive to heat, light and abrasion. Thermal transfer uses a heated ribbon to transfer ink to the label and is listed for cold storage and freezer applications.

Installation on board

• Adhesive is often the weak point. Standard adhesives do not bond to cold, wet or iced surfaces. Specify the application temperature (the temperature of the box when labelled) and the service temperature (hold or cold store) with the label supplier.
• Apply to a dry spot. Label a defined, wiped area of the box or crate, or use a tag or insert where surfaces are always wet.
• Protect the printer, not only the label. Most label printers are office or industrial devices without a high degree of protection against water; place them in a sheltered, drained enclosure away from direct wash-down. Ingress protection codes are defined in IEC 60529.
• Watch condensation. Moving a cold printer or label roll into warm, humid air causes condensation on the printhead and media.
• Choose resolution for the smallest element. Common printheads are 8 dots/mm (203 dpi) and 12 dots/mm (300 dpi). Higher resolution helps for small text and 2D codes.

Materials and wash-down design are covered in more depth on the hygiene and materials hub.

Designing labels in ZPL

ZPL (Zebra Programming Language) describes a label as a sequence of text commands, which makes it well suited to templates where a scale fills in weight, lot and date at print time. Most ZPL commands consist of a caret character followed by a short code; in the table below the caret is left out for readability. A label starts with the XA command and ends with XZ, and each field has a position, a font or barcode command and its data.

In mode D the printer starts the symbol with FNC1, strips the brackets from the encoded data and prints them in the human-readable line; a special invocation code inserts an FNC1 separator after a variable-length AI when another AI follows (Zebra ZPL documentation, Code 128 command). The illustrative layout below is for a 150 × 100 mm label on an 8 dots/mm printer, which gives a print width of 1,200 dots and a label length of 800 dots. The GTIN is an example number, not a real product.

With a module width of 3 dots on an 8 dots/mm printer, each narrow module is 0.375 mm wide. Check that the complete symbol, including quiet zones, fits the label width before sending the template to the vessel. In a live template, the weight, lot and date fields are variables filled by the scale or registration system rather than fixed text.

How WPL approaches this

The R10 Configuration Panel lets users create and manage custom labels in ZPL with a preview function, so the layout can be checked before printing and less label stock is wasted. Once a design is complete, the panel is connected to the printer via USB to upload the label, and the label is assigned to the correct preset. Scales such as the M2 Series Marine Scale connect to label printers, and the R50 Catch Label System combines catch registration with labelling. Which label content a given product and market requires remains the responsibility of the operator. See also the onboard processing hub and the data integration hub.