Marking / Labelling

Along with the inventory / identification of an object, marking / labelling is the second pillar of an object’s “identity”.


Use & importance

Markings are visible traces or impressions. They may be specific to an object, allowing for ease of identification, or more generally applicable to a range of objects, e.g.:  a logo on vases from a specific manufacturer. In general terms, markings are symbols, names or other identifiers. Markings may also refer to the stamping of inventory numbers on objects when recording them.

Assigning an identification number to a cultural good allows the linking of the object with its documentation in order to classify the information. Cultural property marking must be the centre of particular attention in order to ensure the identification of the item and the management of the collection, while maintaining their state of conservation, the following of their documentation. In this regard, marking should be ruled by a marking system in compliance with the inventory system of the collection or with national standards. In the absence of such a system, it is advisable to follow the internationally accepted standards.

Every item should carry its identity number at all times. This allows for direct linkage between the object and the information the museum has on it. The loss of the identity number can entail not only inventorying problems, it can have serious consequences when trying to recover an object in case of theft and proving its ownership. As a matter of fact, markings are an invaluable asset for investigation purposes. Writing a number directly on a museum’s object is therefore the most secure method of labelling.

Markings systems on cultural goods can be divided into three categories:

  • Identification marking, traditional marking of inventories numbers (ink, indelible marker, paint, etc.).
  • Management marking which refers to recent new technologies, using automatic identification tools (bar code, etc.).
  • Security marking to authenticate pieces of art, preventing them from theft (scientific imagery technic, pigment based security ink, etc.).

Marking products must be easy to set up, readable without using an optical pickup apparatus, stable so as to not deteriorate the medium and durable for resisting to deletion. Different methods to attach a mark on a cultural good exist. Generally speaking, it appears that no one marking product answers in an optimum way to the need not to alter the object. Compromises must then be made, in accordance with the needs of the object itself.


Marking vs. Labelling

Spectrum Advice states that “marking and/or labelling an object should be done as part of the accessioning process only or as part of the process to transfer an item to your handling or support collection. In this regard, items on loan or not yet accepted into the collection should not be marked. Items which do not belong to the museum, such as loans or potential donations, should be labelled rather than marked.”

Marking is always preferred, though it is generally accepted that for certain given objects this might not be possible. In order to make the right choice, several factors should be evaluated:

  • Security: The chances of accidental removal must be extremely low.
  • Reversibility: It should be possible for a label or mark to be removed intentionally by the museum.
  • Safety of the object: Neither the materials nor the method should risk significant damage.
  • Discretion but visibility: The methods should not adversely affect the appearance of the object, nor obscure any important detail. At the same time the marked number should be visible enough reduce the need to overly-handle the object.
  • Convenience and safety for the staff: Materials should be easily available and safe.


General rules

In all cases, some general rules apply:

  • Numbers are the connection between objects and documents related to them. They must therefore be physically attached or applied to the objects.
  • To apply the number to the object a secure and safe method should be used.
  • If a temporary number has to be associated with an object, removable tags can be used.
  • Labelling and marking of objects should be done by trained employees. Enough time should be allowed to do it consistently. A restorer-conservator should be consulted when necessary.
  • The mark should be secured, though it should be possible to remove it. The number should be easy to locate without unnecessary handling or defacing of the object.
  • The range of methods and materials in use should be kept to a minimum.
  • When an object is composed of several different materials, the number should be applied to the most secure place, given the method used.
  • When an object consists of several components likely to be dismantled or separated, each part should be numbered. The same applies to fragments of a broken object.
  • A museum should set out its numbering rules in a report that is made available to all relevant staff members.
  • Old inventory numbers should not be removed, as they allow for the tracing of the object’s history. Moreover, old number(s) should be recorded in the documentation.

With regards to the position of the marking or label:

  • As far as possible, all numbers should be applied to the same position on a given type of object.
  • The mark should be easy to locate.
  • Fragile or heavy objects should not have to be picked up to find the number.
  • Large objects might need to be numbered in more than one place or to have extra temporary paper tags when not on display.
  • If an object is stored in package, the number should be repeated on the packaging material.
  • The number should be placed in a position where it does not affect the object's appearance.
  • To small objects only a distinctive part of the number can be applied, or applied on the package.
  • In order to avoid accidental removal of the number, it should not be applied to physically unstable surfaces.

With regards to the methods:

  • The application of a number should not involve a risk of permanent damage to the object.
  • Choose a position so that the number is unlikely to be visible when the object is on display but is accessible in storage.
  • The number should be easily readable. Generally, black characters are used on a light background, white characters on a dark background. Red characters are an alternative.
  • Where duplicate marks are made these should be in different positions on the object.
  • It is recommended to include the number in some of the object's photographs.
  • Specific methods should be used, depending on the object's physical aspects.
  • With composite objects, mark the part on which the most secure method can be used.
  • Sensitive surfaces should be handled with special care.
  • Always consult with a restorer-conservator before using chemical substances.
  • Avoid burning or scratching the numbers on wood or metal, screwing a metal plate on wood, using stamps or inks on paper products, using ink or paint on textiles, applying adhesive labels without protective coating, and using metal edged tags or wires which may rust with time.
  • Avoid unstable surfaces, or placing labels or marks across a line of weakness or fracture.
  • Avoid decoration and painted/varnished/pigmented/waxed areas.


Basic techniques for applying markings

Some traditional systems still persist in some institutions. These traditional practices often have the default to mark the object irreversibly. Graphic pencils are the best example of these traditional methods still in use.

More complex methods can be used with very fragile objects, such as archaeological artefacts, or with very small objects.

The evolution of the artistic practices also imposes to adapt the marking systems. The marking of installations sometimes represents a real challenge. You can’t mark an installation as you would mark a painting.

A range of new techniques to mark a cultural property exist nowadays. For example, radio-frequency identification system allows to stock data thanks to an antenna associated to an electronic chip which can be stuck or incorporated in the art works. The use of x-rays or fluorescent lights is also recommended.

Below are the most common techniques use by art and heritage professionals:

  • Writing on the object, with a traditional material or UV security marker pens.
  • Sticking a label on the object.
  • Sewn on label
  • Submersible label (for specimens preserved in fluid)
  • Water submersible label (for objects stored in water)
  • Label on pin (for pinned biological specimens)
  • Loose label (for small objects such as coins)
  • Tie-on label
  • Duplicated pencil mark
  • Number applied with paint
  • Marking packaging or support
  • Mixing the varnish


Labelling and marking kits

It is useful, and ideal, to have a permanently assembled kit for marking and labelling collections. This ensures that the appropriate materials are right on-hand when needed and at a moment’s notice, and that the choice of materials always remains the safest one.

The following is a list of generally necessary items. Other specific items may be required depending on the needs of the collection, and some of the suggestions below may not apply to yours. The kit should thus be adapted to the objects stored.

Please note that chemicals and solvents should always be stored upright in sealed and labelled containers. The box itself should be clearly marked with its contents, and stored in a secure, cool, well-ventilated area.


  • A copy of the national labelling and marking guidelines, in-house standardised labelling procedures, and information on all chemicals present in the kit
  • Graduated vessel/measuring jug, stirring rod, glass pipettes
  • Safety glasses
  • Gloves for object handling (vinyl or cotton)
  • Drawing/marker felt-tip pens, pencils, sharpeners, erasers, black and white drawing inks, drawing pens
  • Cotton buds
  • Labels (various types, including those resembling Aquascribe and Aquascribe waterproof labels), acid-free paper
  • Tags (such as those produced by Tyvek), unbleached cotton tape, sewing needles, cotton or polyester thread, stainless steel dressmaker’s pins, scissors
  • Paint and brush
  • Starch Paste
  • Polythene artefact bags and muslin bags (various sizes)
  • Hotplate stirrer (if there is a possibility that it need to be used, this will mainly depend on the adhesives chosen)


  • Acetone, white spirit or Stoddard solvent and distilled water or de-ionised water in sealed and labelled containers
  • Ready mixed 20% Paraloid B72 in acetone in sealed and labelled container and Paraloid B72 granules
  • Ready mixed 20% Paraloid B67 in white spirit or Stoddard solvent in a sealed and labelled container