Understanding Preventive Conservation

Preserving history begins at home

Preventive conservation is the practice of reducing or preventing damage to historical objects before deterioration occurs. Rather than treating an artifact after damage has happened, preventive conservation focuses on the environment, handling practices, storage, display and documentation surrounding the object.

For private collectors, these principles can make a significant difference in preserving the character and condition of an artifact for years to come.

Why preventive conservation matters

Historical objects have often survived for decades, centuries or even thousands of years. However, their continued survival depends greatly on how they are handled and stored today.

Prepared by:

Relic & Rarity Curatorial Team

Reviewed by:

Jordan Thomas, Founder and Head Curator

Last updated:

July 2026

Editorial note:

This guide draws upon preventive-conservation principles published by recognized conservation and museum organizations. It is reviewed periodically as professional guidance evolves. Preserving history is central to Relic & Rarity and our mission.

How to handle historical artifacts safely

Many instances of artifact damage occur during ordinary handling, relocation or cleaning. Before lifting an object, consider its weight, balance, fragile areas, previous repairs and the safest route to its destination.

Before handling an artifact

• Remove watches, bracelets, rings and loose clothing that could scratch or catch the object.
  
• Clear the route and prepare the destination before lifting anything.
  
• Inspect the object for cracks, loose fragments, unstable restoration or flaking surfaces.
  
• Use two hands and support the object from beneath.
  
• Move one artifact at a time.
  
• Ask another person to assist with large, heavy or awkward objects.
  
• Never lift an object by a handle, rim, projecting limb, weapon grip or previously repaired section.
  
• Keep food, beverages and cleaning products away from the handling area.
  

Clean hands or gloves

Clean, dry hands are often appropriate for stable stone, ceramic and some glass objects because they provide better grip. Gloves may be advisable for metals, photographs, polished surfaces, ivory, bone and objects that may be affected by fingerprints or skin oils.

Glove selection should match the object. Poorly fitting cotton gloves can reduce grip and increase the possibility of dropping smooth objects. Clean nitrile gloves may offer better control in many situations.

The Smithsonian specifically recommends preventing fingerprints and hand oils from contacting sensitive materials and provides material-specific handling advice for objects such as ivory and paintings.

Never handle an object by

• A ceramic handle
  
• A vessel’s rim
  
• A sword hilt or scabbard fitting
  
• A sculpture’s arms or projections
  
• A frame’s decorative top edge
  
• A loose restoration
  
• A wire, hanger or old mounting fixture
  
• A horn, tusk, feather or attached ornament

Explore artifacts across different materials, sizes and forms, then consider how the handling principles in this section would apply to each object.

Where should historical artifacts be displayed?

A visually attractive location is not necessarily a safe location. The best display area should be stable, secure and protected from environmental extremes.

Avoid displaying artifacts

• In direct sunlight
  
• Immediately beside a window
  
• Above a fireplace
  
• Near a radiator, furnace vent or air-conditioning register
  
• In a damp basement
  
• In an uninsulated attic
  
• Directly beneath plumbing
  
• Near cooking grease, smoke or airborne pollutants
  
• In high-traffic areas where objects may be bumped
  
• On unstable shelving or near the edge of furniture
  
• Within reach of pets or young children
  

Exterior walls, windows and heating vents can expose objects to larger temperature and humidity fluctuations. Choose an interior location whenever practical.

Recommended display approach

Use a stable shelf, pedestal or cabinet appropriate for the object’s size and weight. Heavy pieces should be placed at lower levels whenever possible. Fragile objects should not be positioned near doors, narrow passageways or areas where bags, clothing or furniture may strike them.

Discover historical objects suited for thoughtful display.

Preventive conservation is the practice of reducing or preventing damage to historical objects before deterioration occurs. Rather than treating an artifact after damage has happened, preventive conservation focuses on the environment, handling practices, storage, display and documentation surrounding the object.

For private collectors, these principles can make a significant difference in preserving the character and condition of an artifact for years to come.

Why preventive conservation matters

Historical objects have often survived for decades, centuries or even thousands of years. However, their continued survival depends greatly on how they are handled and stored today.

Explore historical paintings and light-sensitive works.

Environmental stability

Collectors often focus on a single ideal temperature or humidity number. In practice, stability is often more important than trying to maintain one exact level for every object.

Rapid or repeated changes can cause materials to expand and contract. Wood may split, veneers may lift, paint may separate, paper may distort and metal corrosion may accelerate under unsuitable conditions.

The Canadian Conservation Institute explains that high relative humidity can encourage mould, corrosion and physical damage, while very low humidity can contribute to drying and cracking in vulnerable organic materials.

General household guidance

• Maintain a reasonably stable indoor environment.
  
• Avoid rapid temperature or humidity changes.
  
• Do not place objects directly beside heating or cooling systems.
  
• Use a digital temperature and humidity monitor in important display or storage areas.
  
• Address leaks, condensation and dampness promptly.
  
• Avoid storing artifacts against cold basement walls.
  
• Do not use a humidifier directly beside a historical object.
  
• Watch for seasonal changes, especially during Canadian winters and humid summers.
  

Signs of excessive humidity

• Musty odour
  
• Mould growth
  
• Active metal corrosion
  
• Damp surfaces
  
• Swelling or distortion of wood
  
• Cockling or rippling paper
  
• Condensation inside display cases
  

Signs of excessively dry conditions

• New cracks in wood
  
• Lifting veneers
  
• Splitting leather
  
• Brittle textiles
  
• Flaking paint
  
• Shrinkage around joints
  

A climate-controlled display case may be appropriate for sensitive or exceptionally valuable objects, but enclosures should be constructed from conservation-appropriate materials.

See why historical glass requires a stable environment.

Mounts and supports

A good display mount supports an artifact without placing pressure on fragile areas or distracting from the object.

A suitable mount should

• Support the artifact’s weight evenly
  
• Prevent tipping, sliding or rolling
  
• Avoid stress on repaired or fragile areas
  
• Use stable, non-staining materials
  
• Fit the object without excessive pressure
  
• Be removable without damaging the artifact
  
• Allow the object to be lifted safely
  
• Remain visually unobtrusive
  

Avoid

• Bare metal contacting delicate surfaces
  
• Adhesive tape
  
• Hot glue
  
• Household putty that may stain
  
• Screws placed into an artifact
  
• Tight wire wrapped around an object
  
• Acidic cardboard
  
• Raw wood touching porous artifacts
  
• Foam that is crumbling, sticky or strongly scented
  

Small amounts of conservation-appropriate museum wax or mounting material may be useful for certain stable decorative objects, but it should never be treated as a universal solution. Heavy, valuable or irregularly balanced objects should have a professionally fabricated mount.

Wall-mounted artifacts

Historical weapons, shields, framed art and reliefs require secure fixings appropriate for both the artifact and the wall construction. Do not rely solely on decorative hooks, old picture wire or adhesive hanging strips.

View arms, armour and objects requiring secure display supports.

Should you clean an ancient or historical artifact?

In many cases, the answer is no.

Surface deposits, oxidation, patina, wear, burial accretions and previous labels may contain historical evidence. Cleaning can permanently remove original material, alter the appearance of an artifact and reduce both its research and collector value.

Never use

• Bleach
  
• Vinegar
  
• Lemon juice
  
• Furniture polish
  
• Silver polish
  
• Brass cleaner
  
• Commercial rust remover
  
• Abrasive pads
  
• Toothpaste
  
• Household oils
  
• Soap and water without material-specific advice
  
• Pressure washing
  
• Ultrasonic cleaning
  
• Strong solvents
  
• Wire brushes
  
• Power tools
  

Avoid polishing historical metals

A dark or aged surface is not necessarily dirt. Patina may be stable, historically important and desirable. Polishing bronze, brass, copper, silver or iron can remove original surface material and decorative detail.

Light dusting

A stable artifact may sometimes be lightly dusted using a clean, very soft brush while supporting the object securely. Dust should be brushed away from fragile details rather than forced into cracks.

Do not dust an object if the surface is:

• Flaking
  
• Powdery
  
• Cracked
  
• Soft
  
• Lifting
  
• Decorated with loose pigment
  
• Covered with unstable corrosion
  
• Previously restored and uncertain
  

The Canadian Conservation Institute advises that extensive cleaning and repairs should be referred to a conservator and notes that products marketed for household care can cause harm.

Never attempt to improve an artifact’s appearance before determining whether the surface is original, stable or historically significant. Discover why original surfaces matter to authentication and provenance.

How to Care for Different Types of Artifacts

Pottery, Terracotta and Ceramics

Ceramic objects are generally stable, but they remain vulnerable to impact, unstable repairs, soluble salts and damage from improper handling.

Care recommendations

• Support vessels from the base rather than the rim or handles.
  
• Do not lift amphorae, jugs or cups by their handles.
  
• Use padded supports for rounded or uneven bases.
  
• Keep archaeological ceramics away from damp conditions.
  
• Do not soak pottery or terracotta.
  
• Avoid filling ancient vessels with water, flowers, soil or food.
  
• Watch for powdery surfaces, salt crystals, flaking slip or opening cracks.
  
• Do not remove burial deposits without specialist advice.
  

Ceramic and glass objects require preventive care based on their condition, materials and environmental risks.

Ancient and Historical Glass

Glass can appear stable while remaining highly vulnerable to impact, previous repairs and environmental deterioration.

Care recommendations

• Handle with clean hands or well-fitting nitrile gloves.
  
• Support the entire object from below.
  
• Never lift glass by the neck, rim or handle.
  
• Use a padded mount for vessels with irregular bases.
  
• Keep glass away from shelf edges.
  
• Do not wash archaeological or iridescent glass.
  
• Avoid sudden temperature changes.
  
• Do not attempt to reattach loose fragments.
  
• Watch for weeping, cloudiness, fine cracking or flaking surfaces.
  

Iridescence on ancient glass may be a product of surface alteration. It should not be scrubbed or polished away.

Bronze, Copper and Brass

Metal surfaces often carry stable oxidation and patina that should be preserved.

Care recommendations

• Handle with clean nitrile gloves when practical.
  
• Keep metals dry and away from damp storage.
  
• Do not polish archaeological bronze.
  
• Avoid commercial metal cleaners.
  
• Monitor for new powdery green corrosion.
  
• Keep metal objects away from acidic wood, cardboard and unstable foams.
  
• Do not apply oil, wax or lacquer unless advised by a conservator.
  
• Support projecting elements and thin cast sections.
  

Bright, pale-green powder that appears to grow or return after removal may indicate active corrosion and should be professionally assessed.

Iron, Steel, Arms and Armour

Iron is especially sensitive to moisture and salts. Corrosion can remain active beneath the surface.

Care recommendations

• Maintain a stable, dry environment.
  
• Handle with clean gloves to reduce fingerprints and salts.
  
• Do not scrape or wire-brush corrosion.
  
• Avoid household gun oils on archaeological or decorated surfaces.
  
• Support swords horizontally at multiple points.
  
• Do not hang heavy weapons from fragile hilts, guards or scabbards.
  
• Keep blades and armour away from condensation and exterior walls.
  
• Inspect joints, rivets, leather straps and wooden components regularly.
  
• Use custom mounts for helmets, shields and armour.
  

Before displaying firearms, confirm all applicable legal, licensing and storage requirements. Conservation guidance does not replace legal obligations.

Stone, Marble and Architectural Fragments

Stone may be heavy and durable, but weathered, excavated or previously repaired stone can be fragile.

Care recommendations

• Support the object’s full weight.
  
• Use a pedestal rated for the load.
  
• Avoid lifting by carved projections.
  
• Keep porous stone away from liquids and staining materials.
  
• Do not use household stone cleaners.
  
• Do not pressure-wash or aggressively scrub.
  
• Inspect for powdering, salt deposits and opening repairs.
  
• Secure tall or top-heavy pieces against tipping.
  
• Use professional installation for heavy wall fragments.

Wood and Painted Wood

Wood responds to changes in humidity and may contain fragile paint, gesso, veneers or old repairs.

Care recommendations

• Maintain stable environmental conditions.
  
• Keep wood away from direct heat and strong sunlight.
  
• Do not apply oils, sprays or furniture polish.
  
• Avoid damp cloths on painted or unfinished surfaces.
  
• Support carved projections when moving.
  
• Monitor for new cracks, lifting paint, powder or insect holes.
  
• Use barriers between wood and metal display supports.
  
• Do not place wooden objects directly on damp masonry.
  

The Canadian Conservation Institute emphasizes that wood does not need to be “fed” with oils and that stable environmental conditions are more important than household treatments.

Paintings, Icons and Devotional Panels

Paintings may contain canvas, wood, fabric, gesso, pigments, varnish and previous restoration.

Care recommendations

• Handle one painting at a time.
  
• Carry framed works with both hands from the sides and bottom.
  
• Never lift a frame by its decorative upper edge.
  
• Keep paintings away from direct sunlight and fireplaces.
  
• Do not clean paint surfaces with water or household products.
  
• Avoid touching the painted surface.
  
• Inspect for lifting paint, cracking, distortion, mould or loose frame components.
  
• Use secure wall hardware appropriate for the object’s weight.
  
• Request assistance when moving large works.
  

Smithsonian conservation guidance recommends careful handling and multiple people for large panels or canvases.

Paper, Manuscripts, Maps and Documents

Paper is vulnerable to light, moisture, acidity, pests and improper framing.

Care recommendations

• Handle with clean, dry hands.
  
• Keep food and beverages away.
  
• Store flat wherever practical.
  
• Use acid-free folders, boxes and backing materials.
  
• Avoid pressure-sensitive tape and household adhesives.
  
• Do not laminate historical documents.
  
• Frame with conservation-quality materials.
  
• Keep the paper from touching glazing.
  
• Limit light exposure.
  
• Never fold a document along an old crease.
  
• Avoid rolling brittle paper.
  

The Canadian Conservation Institute recommends cool, stable storage and keeping general paper collections below 50% relative humidity where practical, while emphasizing that environmental needs depend on the collection and setting.

Photographs and Early Photographic Images

Daguerreotypes, ambrotypes, tintypes and early photographs can be extremely sensitive to handling and environmental conditions.

Care recommendations

• Do not touch the image surface.
  
• Keep original cases and protective glazing intact.
  
• Avoid opening sealed photographic packages.
  
• Store away from strong light and moisture.
  
• Do not use household glass cleaner near the image.
  
• Support cases from beneath.
  
• Store damaged photographs in archival enclosures.
  
• Contact a specialist if the image appears loose, tarnished or unstable.

Textiles, Leather and Organic Materials

Organic materials are often highly responsive to light, humidity, pests and physical stress.

Care recommendations

• Limit light exposure.
  
• Avoid hanging heavy textiles from a small number of points.
  
• Use padded supports.
  
• Do not fold brittle textiles or leather.
  
• Keep away from damp areas.
  
• Check periodically for insects, webbing, larvae or fresh powder.
  
• Avoid leather dressings, oils and conditioners unless recommended professionally.
  
• Do not stretch old textiles tightly into frames.
  
• Use dust covers or display cases when appropriate.
  

The Canadian Conservation Institute recommends protecting textiles from both dust and light through suitable enclosures and covers.

Bone, Ivory, Horn, Antler and Teeth

These materials may split, delaminate, stain or react to environmental change.

Care recommendations

• Handle with clean gloves or freshly washed hands.
  
• Avoid prolonged exposure to strong light.
  
• Maintain stable environmental conditions.
  
• Do not soak or bleach.
  
• Do not apply oils.

• Support thin, carved or projecting areas.
  
• Avoid placing these materials against unstable wood or coloured fabrics.
  
• Watch for splitting, lifting layers, powder or insect damage.
  

Wildlife-derived materials may also be subject to CITES and other import, export or ownership regulations. Care guidance does not determine legal status.

Fossils, Minerals and Natural-History Specimens

Natural-history objects can include stone, bone, shell, mineral crystals, adhesives and old restoration materials.

Care recommendations

• Support heavy specimens from below.
  
• Use padded trays or stable mounts.
  
• Keep labels and provenance records with each specimen.
  
• Do not wash specimens without knowing their mineral composition.
  
• Avoid household sealants.
  
• Store fragile pieces separately to prevent contact damage.
  
• Keep pyrite-bearing specimens in stable, dry conditions.
  
• Watch for powder, cracking, odours or expanding corrosion products.
  
• Avoid handling fossils by projecting teeth, horns or thin matrix areas.
  

The Canadian Conservation Institute recommends individual padded supports and inert dividers for fragile natural-history specimens.

How to Store Historical Artifacts

Storage areas should be clean, stable, secure and protected from water, pests and physical damage.

Recommended storage practices

• Keep objects off the floor.
  
• Use shelves capable of supporting the weight.
  
• Place heavier objects on lower shelves.
  
• Use padded trays for small or fragile artifacts.
  
• Separate objects so they cannot strike one another.
  
• Use acid-free tissue, folders and boxes where appropriate.
  
• Label storage locations clearly.
  
• Avoid overcrowding.
  
• Keep an inventory of boxed objects.
  
• Protect objects from dust without sealing in moisture.
  
• Inspect storage areas periodically for leaks, pests and environmental changes.
  

Avoid long-term storage in

• Shipping cartons
  
• Bubble wrap directly against delicate surfaces
  
• Plastic bags containing trapped moisture
  
• Newspaper
  
• Damp basements
  
• Hot attics
  
• Garages
  
• Exterior sheds
  
• Foam that is crumbling or sticky
  
• Wood cabinets with strong chemical odours
  

Packing materials intended for transport are not always appropriate for permanent storage. The National Park Service advises against permanently storing museum objects in transportation packing containers.

Safely unpacking a newly acquired artifact

Before opening a shipment, prepare a clean surface large enough for the object and all packaging materials.

Recommended process

1. Photograph the unopened package if there is visible damage.
   
2. Open the outer carton carefully without inserting a blade deeply.
   
3. Remove loose packaging gradually.
   
4. Do not pull an object from its wrapping by a projecting element.
   
5. Identify the base and strongest supporting areas.
   
6. Lift the artifact with two hands.
   
7. Retain all documentation, labels and provenance information.
   
8. Inspect the object under good lighting.
   
9. Compare it with the condition shown in the listing photographs.
   
10. Keep appropriate packaging for future transport, but do not automatically use it as permanent storage.
    

After arrival

Allow sensitive objects to adjust gradually after exposure to very different outdoor temperatures. Avoid placing a cold object immediately beside a heater or opening a chilled package in a hot, humid room.

Report suspected transit damage promptly and retain the packaging until the matter is resolved.

Learn how Relic & Rarity prepares artifacts for secure worldwide delivery.

Warning signs that an artifact may be deteriorating

Regular observation allows collectors to identify changes before damage becomes severe.

Look for

• New cracks
  
• Lifting or flaking paint
• Changes in colour or gloss
  
• Powdery surfaces
  
• Loose fragments
  
• Fresh rust
  
• Bright green corrosion
  
• White crystalline deposits
  
• Mould or musty odours
  
• Insect holes or fine powder
  
• Distortion or warping
  
• Condensation in a display case
  
• Loose mounts
  
• Opening restoration joins
  
• Staining from display materials
  
• New brittleness
  

Photograph each object periodically from the same angles. Comparison photographs can make gradual changes easier to identify.

Do not repeatedly touch or test a suspicious area. Isolate objects affected by mould or insects and seek appropriate professional advice.

See how material condition and historical evidence are evaluated.

Documenting your collection

Collection care includes protecting the historical and ownership information associated with each object.

The Smithsonian recommends maintaining a dedicated file for every object because documentation is important for collection management, insurance, theft and disaster recovery.

Keep the following information

• Object title
  
• Culture or region
  
• Approximate date or period
  
• Materials
  
• Dimensions and weight
  
• Detailed description
  
• Condition notes
  
• Provenance and ownership history
  
• Purchase invoice
  
• Certificate of Authenticity
  
• Export or import documentation
  
• Scientific reports
  
• Previous auction or dealer records
  
• Restoration history
  
• High-resolution photographs
  
• Current display or storage location
  
• Insurance valuation, where applicable
  
• Correspondence relating to the object
  

Digital records

Maintain at least one secure backup separate from your primary device. Use clear file names and include the acquisition date or inventory number.

Example:

RR-2026-014-Roman-Bronze-Figure-Front.jpg

Physical records

Store original documents in archival folders away from the artifact when appropriate. Do not attach labels directly to delicate surfaces using pressure-sensitive tape.

Discover what is included in a Relic & Rarity Certificate of Authenticity to add to your collection documentation.

Protecting a collection from theft, fire and water

Conservation includes preparation for sudden events, not only gradual deterioration.

Recommended precautions

• Maintain an up-to-date inventory.
  
• Photograph objects clearly.
  
• Record dimensions and identifying marks.
  
• Review insurance coverage.
  
• Secure high-value displays.
  
• Keep objects away from plumbing and floor level.
  
• Install smoke and water alarms.
  
• Know the location of water shut-off valves.
  
• Avoid overloading electrical outlets.
  
• Maintain clear exit routes.
  
• Keep emergency contact information accessible.
  
• Back up collection records off-site or in secure cloud storage.
  

In an emergency, personal safety comes first. Do not enter an unsafe building to retrieve artifacts.

After water exposure, fire, mould or structural damage, contact appropriate emergency services, insurers and conservation professionals before attempting extensive cleaning.

When should you contact a conservator?

Professional advice should be considered when an object shows active deterioration or when treatment could affect its historical surface.

Contact a conservator when you observe

• Active corrosion
  
• Flaking paint or gilding
  
• Loose fragments
  
• New cracks
  
• Powdering stone or ceramic
  
• Mould
  
• Insect activity
  
• Wet or water-damaged material
  
• Distorted paper or textiles
  
• Failed adhesives
  
• Unstable previous repairs
  
• A loose canvas or panel
  
• Structural weakness
  
• Salt deposits
  
• Significant staining
  
• Uncertain cleaning requirements
  

A conservator can assess the materials, document the condition, recommend preventive measures and determine whether treatment is appropriate.

Conservation versus restoration

Conservation prioritizes stabilization and preservation.

Restoration may involve returning an object closer to an earlier appearance.

The two can overlap, but collectors should understand the proposed treatment, materials, reversibility and effect on the artifact before authorizing work.

Care continues beyond acquisition

Relic & Rarity believes that responsible collecting extends beyond the moment of purchase. Objects acquired from our collection are accompanied by available historical, material and provenance information (when available), together with continued collector support.

Where appropriate, we can help purchasers understand:

• Basic handling considerations
  
• Display orientation
  
• Known restoration
  
• Material-specific concerns
  
• Documentation provided with the artifact
  
• Appropriate professional referrals where specialist conservation is required
  

Important limitation

Relic & Rarity does not recommend invasive cleaning, restoration or conservation treatment without an appropriate condition assessment. Guidance provided through this resource is general and should not replace advice from a qualified conservator.

Important care notice

The information presented in this guide is intended for general educational purposes. Historical objects vary substantially in age, material composition, condition, restoration history and environmental sensitivity.

Relic & Rarity cannot assess an object’s individual conservation needs through this guide alone. Before cleaning, repairing, mounting or treating an artifact, consult a qualified conservator familiar with the relevant material.

Care information does not replace legal requirements concerning firearms, cultural property, wildlife-derived materials, human remains, hazardous substances, import, export, possession or transportation.