CCI Notes 1/5

Applying Registration Numbers to Paintings and Sculptures

Introduction

Museums apply registration, inventory, or accession numbers to each of their objects for the purposes of identification and security. The manner in which these numbers are applied varies according to the type of object.

Many different materials have been used as supports for paintings, including wood panel, canvas on stretcher, and metal sheet. Less common supports, such as ivory or reverse paintings on glass (where the paint layer is on the back of the glass), can present some difficulties when applying registration numbers. General recommendations such as those found in this Note are useful, but common sense is always most important; certain cases may require bending the rules.

Some works of art, such as contemporary paintings without stretchers or paintings on glass, may present problems not covered in this Note. In these cases, consult a conservator.

General Rules

• Before handling, examine the work of art to ensure that it is structurally sound and can be handled safely.
  
  
• Never apply a label to or write on the face of a painting or the reverse of a canvas.
  
  
• Clean the area selected for numbering to improve adherence.
  
  
• Write numbers clearly.
  
  
• The size of the number will vary according to the size of the work of art (e.g., 2 mm high for a miniature, 5 cm high for an oversized painting).
  
  
• To avoid needless handling, the registration number should be easy to find. It should always be placed in the same general location (e.g., lower right corner) on a given type of work of art.

According to personal preference or to the nature of the support, use a technical pen, an indelible marker, or acrylic paint on a fine brush to apply the registration number. Fine technical pens (e.g., 0.25 mm or 0.35 mm) are useful for making very small numbers. Where necessary, apply a coating before and after marking to isolate the substrate and to protect the number. Clear nail polish is often used for this purpose.

• Registration numbers are most frequently written in black. On a dark background, however, white is preferable.
  
  
• Leave old marks and labels in place. Sometimes a museum changes its classification system, and the former number of a piece may have been referred to in previous publications. In these cases, the best solution may be to cross out but not obscure the old number to avoid possible confusion. If the number must be deleted, keep a record of it in the painting's dossier.
  
  
• For a work of art made of several separate pieces, give the same number to each piece and add a letter to differentiate the pieces (e.g., 89.456A and 89.456B).

Procedures

1. Canvas on Stretcher

Location:

Reverse surface of stretcher (e.g., lower right corner). The number may also be written on a backing board if there is one.

Procedure:

• Apply a layer of clear nail polish (optional) to the stretcher, and allow it to dry.
• Write the registration number on the nail polish (if used) or on the wood surface, and allow it to dry.
• Apply a layer of clear nail polish (optional) over the number, and allow it to dry.

2. Wooden Panel

Location:

Reverse surface of wooden panel (e.g., lower right corner).

Procedure:

Same as for Canvas on Stretcher

3. Painting on Metal

Location:

Reverse surface of metal support (e.g., lower right corner).

Procedure:

• If necessary, degrease the selected area using a cotton swab (e.g., Q-tip) dipped in acetone or in ethyl alcohol.
• Apply a layer of clear nail polish, and allow it to dry.
• Write the registration number on the nail polish.
• Apply a layer of clear nail polish over the number, and allow it to dry.

4. Miniature on Ivory

Location of framed:

Place the number in an inconspicuous location on the frame or locket. If there is no suitable location, a paper tag with the number can be attached to the frame or locket with a thread, and can be hidden during display.

Procedure:

Same as for Canvas on Stretcher or for Painting on Metal, depending on the material of the frame. Because ivory paintings are normally small, the number should be of a corresponding size. Using small dots instead of a continuous line may make it easier to form small, neat, readable numbers.

Location if not framed:

An ivory miniature may be thin, translucent, and extremely sensitive to handling. Therefore, it is not generally recommended that the registration number be applied to the ivory itself. Either frame the miniature and write the number of the piece on the frame (as described above) or place the miniature in a box on which the number of the piece is written.

When no registration number is written directly on a piece, it is important to have a careful description and a photograph of the object in the museum dossier to avoid any confusion between pieces.

5. Frame

Location:

Reverse (e.g., lower right corner).

Procedure:

Same as for Canvas on Stretcher. A frame may have its own number. To avoid any confusion between the frame number and the registration number of the painting, include "Frame No ---" or a notation such as "----F" to distinguish it as being the frame number.

6. Polychrome Sculpture

Location:

The registration number should be written in a discrete, unpainted area on a part of the sculpture not meant to be seen, such as near the bottom at the back. Only in exceptional cases (e.g., where no bare support material is exposed) should the number be placed under the base of the sculpture. In addition, to minimize handling and to facilitate identification during storage, a paper identification tag held by a soft string may be looped over a part of the piece. Avoid fragile areas that may be damaged easily.

Procedure:

Same as for Canvas on Stretcher, assuming that there is no point on the selected area.

7. Metal Sculpture

Location:

Same as for Polychrome Sculpture.

Procedure:

Same as for Painting on Metal.

Materials

• technical pens (e.g., Pigma Pens or Rotring Rapidograph pens with different tips: 0.25 mm, 0.35 mm, etc.); fine, indelible markers; black or white acrylic paints and fine paintbrushes (e.g., 00 or 000)
  
  
• clear nail polish
  
  
• paper tie-on tags without metal rings or Tyvek

Bibliography

1. Dudley, Dorothy et al. Museum Registration Methods. Third rev. ed. Washington: American Association of Museums, 1979.
   
   
2. Krahn, Ann Howatt. [unpublished notes].

Copies are also available in French.

Texte également publié en version française.

© Government of Canada, 1994
Cat. No. NM95-57 / 1-5-1994E
ISSN 0714-6221