This handbook complements the National Gallery of Art's publication Art in Transit: Studies in the Transport of Paintings, prepared for the International Conference on the Packaging and Transport of Paintings, held in London, September 9-13. This handbook is designed to allow for updates and revisions to be made to sections.
ASSESSING RISKS
Topics
CRITERIA FOR THE SELECTION OF PAINTINGS FOR LOAN
Glazing (Optional)
34;False Ra~et" - Glazing Retainer
Backing Board
What conditions the case is expected to encounter during the transit phase of the loan. The frame rabbit must be padded to prevent the edge of the painting from fraying.
SELECTION CRITERIA FOR FRAMES
The backing can be made of cork or felt, glued into a bunny or a protective strip attached to the edge of the picture.
SELECTION CRITERIA FOR PAINTINGS ON CANVAS OR PAPER MOUNTED ON CANVAS
Ground
The painting should have a sturdy support plate attached to the back of the frame or stretcher frame. A weak cloth can come into contact with the stretcher frame and cross beams, damaging the paint.
ADDITIONAL ISSUES FOR LARGE PAINTINGS ON CANVAS
The painting can be larger than the usual easel painting and often the width and thickness of the stretcher members is insufficient to support the weight of the canvas. There must be no unrepaired tears in the canvas, especially along the sides of the stretcher.
SELECTION CRITERIA FOR CONTEMPORARY PAINTINGS ON CANVAS
The stretcher of some large contemporary paintings is constructed so that they split in the center and allow painting. The unusual construction and dimensions of contemporary paintings can make packaging more difficult as some pieces may be three-dimensional objects that require special packaging.
SELECTION CRITERIA FOR PAINTINGS ON RIGID SUPPORTS
Hardboard, Paperboard, or Academy Board
Layered structures such as these are sensitive to changes in relative humidity, which can cause the layers to move. Rigid supports are sensitive to extreme relative humidity, which causes dimensional movement of the materials, leading to warping and delamination.
PAINTINGS ON WOOD, IVORY, OR BONE
There must be no splits or checks on the panel along the fixed elements of the cradle. The plate must not be twisted between the fixed parts of the support.
PAINTINGS ON METAL AND OTHER NONPOROUS RIGID SUPPORTS
Metals, Stone, Polymers, Ceramics, Glass, Etc
The painting should not have a history of chronic instability of the support or paint layer, such as recurrent paint peeling. In the case of paintings on rigid supports such as metal, ceramic or stone, they are even more vulnerable to impacts than many panel and canvas paintings.
NOTES
TRANSIT CLIMATE CONDITIONS
EXPECTED TRANSIT ENVIRONMENTS IN SUMMER AND WINTER
Record high/low temperatures versus average relative humidity for the fifty United States and its possessions. Saunders, "Temperature and Relative Humidity Conditions Encountered in Transportation," Art in Transit: Studies in the Transport of Paintings (1991).
TEMPERATURE PROTECTION
INSULATING MATERIALS
VALUES
When comparing the properties of various materials, the R-value for a specified material thickness is provided. When an R-value is given for a wall in a house, it refers to the insulating properties of the total thickness of all the materials in the wall.
The R-value is a measure of a material's ability to resist heat flow, with higher R-values providing better insulation. Wilson, "Temperature and Relative Humidity Control in Packing Cases," UKIC Meeting on Packing Cases--Safer Transport for Museum Objects Preprints, P.
TEMPERATURE HALF-TIME
TIME
The simplest approach is to place a recording device inside the case that monitors the internal temperature and then move the case from a room at one temperature to a room at a much different temperature. The recorded temperature history will reveal the time it took for the matter to reach the midpoint between the initial and final temperatures.
TEMPERATURE HALF-TIMES OF PACKING CASES
34; Temperature and relative humidity control in packaging boxes", UKIC Meeting on Packing Cases - Safer Transport for Museum Objects Preprints, S.
RELATIVE HUMIDITY PROTECTION
WRAPPING MATERIALS FOR PAINTINGS
POLYETHYLENE
WRAPPING MATERIALS FOR PAINTINGS: GLASSINE
KRAFT PAPER
WRAPPING MATERIALS FOR PAINTINGS: KRAFT PAPER OR GLASSINE COVERED WITH
WRAPPING MATERIALS FOR PAINTINGS: INNER PACKING CASE
GENERAL PROPERTIES OF SILICA GEL
USE OF SILICA GEL IN PACKING CASES FOR PAINTINGS
Due to the small amount of air in the packaging, and because most paintings are made of materials that absorb moisture, silica gel is usually an unnecessary addition to the packaging. Silica gel that has been conditioned to the wrong relative humidity can be mistakenly added to the packaging box.
SHOCK AND VIBRATION HAZARDS
Transfer from the museum or gallery by a truck to the terminal of the long-distance carrier, such as at an airport. Vibrations due to trucks that are not equipped with air suspension are the most severe of any transportation system, in the range of 1-200 Hertz (cycles per second).
VIBRATION FRAGILITY OF PAINTINGS
Tumosa, "An Introduction to the Mechanical Behavior of Paintings under Rapid Loading Conditions," Art in Transit: Studies in the.
SHOCK PROTECTION
FRAGILITY FACTORS
Computer modeling of similar paintings and materials by the Smithsonian Institution's Conservation Analytical Laboratory predicted similar damage at shock levels in the range of 90 Gs. Canvas paintings without frames were most sensitive to impacts on their corners, impacts on the portable perpendicular to the canvas, and impacts due to tipping or tipping hazards.
PROBABLE DROP HEIGHTS
Handles reduce drop height by lowering the container height relative to the floor during handling. There is always a possibility that the drop heights in Table 1 will be exceeded during a shipment.
HOW TO USE A DYNAMIC CUSHIONING CURVE
PROCEDURE A
Calculating the Shock Protection Provided by a Packing Case
To estimate the most likely fall height that could occur during transport, the total weight of the painting and its packaging is needed. Consult the dynamic damping curve for the selected damping material and drop height.
PROCEDURE B
Calculate the static load on the foam on each of the narrow sides of the package. The total weight of the painting, the inner packaging and the outer packaging are needed.
OPTIIVIUM STATIC LOADS m Quick Reference Table
LOAD-BEARING AREAS
In other words, when determining the support area for extended frames, ignore all the frames above the outer "edge" (which can vary from very narrow to very wide). The support area (LBA) is: LBA = Length of frame edge x width of frame molding that supports the weight.
VIBRATION PROTECTION
VIBRATION CONTROL FOR CANVAS PAINTINGS
Backboards
Foam Inserts behind the Painting
Due to the increased weight, greater precautions must be taken to ensure that the foam is securely attached to the board. The foam can be attached to the board with double-sided tape or hot melt adhesive.
Stretcher Lining
Holes are cut in the stretcher lining to allow access to the stretcher wedges (keys). Green, "Shock and vibration test results for framed paintings on canvas supports" ICOM Committee on Conservation 8th Triennial Meeting, Preprints, Sydney (Sept.
PACKING CASES
CASE CONSTRUCTION -- STRUCTURE
The choice of case material is not the only consideration when making a case. If plywood is used as the construction material, the thickness of the plywood has a large effect on the resistance of the casing sides to puncture.
HANDLES
When mounted upside down, hands become trapped between the handle and the housing. Wooden handles are more vulnerable to damage because they protrude from the side of the case.
SKIDS
The long dimension of the slide approximates the long dimension of the packing box. The long dimension of the slide is oriented perpendicular to the long dimension of the packing box.
CHEMICAL STABILITY OF PACKING MATERIALS
The amount of corrosion on the metal strips is compared to that on metal strips from a control test which is identical except for the absence of the material being tested. The vapor barrier around the object also acts as a contamination barrier, protecting the object from most of the volatile substances that can be emitted by the surrounding materials.
SOFT PACKING
Use a wooden collar (travel frame) attached to the back of the painting or frame to protect ornate frames and con-. The truck floor should be padded with clean, moving blankets or more foam before the soft wrap is strapped to the vehicle wall.
SAMPLE PACKING CASE NO. 1
The static load on the back of the painting is probably too low because the back of the painting is in contact with such a large foam surface. The static load on the front of the painting and the four narrow sides depends on the shape of the frame.
SAMPLE PACKING CASE NO. 2
The corner pads attached to the two large sides of the package change the static load on the foam. The corner pads generally improve the static load on the front of the painting.
SAMPLE PACKING CASE NO. 3
Polyethylene foam will provide acceptable shock protection for typical paintings if the proper static load is placed on the foam. It is easy to use too much foam for the corner pads, which produces an improper static charge.
SAMPLE PACKING CASE NO. 4
It is possible to achieve better than 60 G of shock protection for a 75 cm (30 inch) drop height, but the static load must be accurately calculated for the case design. The polystyrene foam adds additional thermal protection for the painting, increasing the temperature of the packaging bag half the time.
SAMPLE PACKING CASE NO. 5
The underside of the case is covered with a second layer of 5 cm (2 in.) pieces of polyester urethane foam. The inner case improves the protection of the painting from accidental puncture if an accident occurs.
SAMPLE PACKING CASE NO. 6
On the two large sides of the package, the polyester urethane foam corner pads are glued to a 5 cm (2 in.) piece of polyester urethane foam. Corner pads attached to the two large sides of the pack change the static load on the foam.
SAIVfPLE PACKING CASE NO. 7
The size of the corner pads can be adjusted to provide the optimal static load of the foam. The inner box improves the protection of the painting against punctures, should the accident happen.
CASE LABELS
PACKING INSTRUCTIONS FRENCH
PACKING INSTRUCTIONS SPANISH
PACKING INSTRUCTIONS GERMAN
DESSELBEN PACKVERFAHRENS UND VORHANDENEM PACKMATERIALS
PACKING INSTRUCTIONS ITALIAN
MATERIALI
ROLE OF THE COURIER
The bidder must have an understanding of the artwork's construction and condition and its special requirements. When handing over the case to the loan museum, the courier must receive a signed receipt.
GLOSSARY
This term usually refers to events that occur perpendicular to the plane of the painting. The edges of the stretcher frame are marked in the paint surface by fairly continuous parallel straight cracks.