pjt222 Preserve Materials
Preserve and conserve library and archival materials through environmental control, proper handling, repair techniques, and disaster preparedness.
When to Use
- You are establishing preservation practices for a new or existing collection
- Materials show signs of deterioration (foxing, brittleness, loose bindings)
- You need to set up environmental controls for a storage or display area
- You are planning digitization to preserve fragile originals
- You need a disaster recovery plan for a library or archive
Inputs
- Required: Materials to preserve (books, manuscripts, photographs, maps, media)
- Required: Current storage conditions (temperature, humidity, light exposure)
- Optional: Budget for preservation supplies and equipment
- Optional: Digitization equipment (scanner, camera, software)
- Optional: Condition survey of existing collection
Procedure
Step 1: Assess Current Conditions
Survey the environment and the materials to establish a baseline.
Environmental Assessment Checklist:
+-----------------------+------------------+---------------------+
| Factor | Ideal Range | Measure With |
+-----------------------+------------------+---------------------+
| Temperature | 18-21°C | Thermometer with |
| | (65-70°F) | min/max recording |
+-----------------------+------------------+---------------------+
| Relative Humidity | 30-50% RH | Hygrometer or |
| | | datalogger |
+-----------------------+------------------+---------------------+
| Light (storage) | <50 lux | Light meter |
| | No UV | |
+-----------------------+------------------+---------------------+
| Light (display) | <200 lux | Light meter + |
| | UV filtered | UV filter readings |
+-----------------------+------------------+---------------------+
| Air quality | Low dust, no | Visual inspection, |
| | pollutants | HVAC filter check |
+-----------------------+------------------+---------------------+
Material Condition Survey (sample 10% of collection):
- Excellent: No visible damage, binding intact, pages flexible
- Good: Minor wear, slight yellowing, binding sound
- Fair: Moderate foxing, some loose pages, spine cracked
- Poor: Brittle pages, detached covers, active mold or pest damage
- Critical: Pages fragmenting, structural failure, immediate intervention needed
Record the percentage in each condition category.
Expected: Baseline data for environmental conditions and material health, identifying immediate risks and long-term trends.
On failure: If monitoring equipment is unavailable, use a basic thermometer/hygrometer from a hardware store. Imprecise data is far better than no data. Prioritize humidity monitoring — it is the single most damaging environmental factor.
Step 2: Establish Environmental Controls
Create and maintain the conditions that slow deterioration.
Environmental Control Priorities (in order of impact):
1. HUMIDITY CONTROL (most critical)
- Target: 30-50% RH, with <5% daily fluctuation
- Too high (>60%): mold growth, foxing, warping
- Too low (<25%): brittleness, cracking, flaking
- Solutions: dehumidifier, humidifier, HVAC control, silica gel
- Monitor continuously with datalogger
2. TEMPERATURE CONTROL
- Target: 18-21°C (65-70°F), with <3°C daily fluctuation
- Lower is better for long-term preservation (slows chemical decay)
- Stability matters more than exact temperature
- Never store near exterior walls, heating vents, or pipes
3. LIGHT MANAGEMENT
- UV radiation causes irreversible fading and embrittlement
- Filter all windows with UV film (blocks >99% UV)
- Use LED lighting (no UV emission) instead of fluorescent
- Keep lights off in storage areas when not in use
- Display items on rotation (3-6 months on, then rest)
4. AIR QUALITY
- HVAC filters: minimum MERV 8, ideally MERV 13
- No food or drink near materials
- Avoid off-gassing materials (fresh paint, new carpet, cardboard)
- Ensure air circulation to prevent microclimate pockets
5. PEST MANAGEMENT (IPM)
- Inspect incoming materials before shelving
- Sticky traps at floor level, checked monthly
- No cardboard boxes (pest habitat) — use archival containers
- If pests found: isolate affected items, freeze treatment
(-20°C for 72 hours kills most book pests)
Expected: Environmental conditions within target ranges, monitored continuously, with documented response procedures for excursions.
On failure: If HVAC is not controllable (rental space, historic building), focus on microenvironments: archival boxes, silica gel packets, and sealed display cases create local climate control even when the room cannot be managed.
Step 3: Handle Materials Properly
Prevent damage from the most common source: human handling.
Handling Rules:
1. Clean, dry hands — no gloves for paper (reduces grip and
dexterity; gloves are for photographs and metal objects)
2. Support the spine: never pull a book by the headcap
- Push neighboring books back, then grip the desired book
by both boards at the middle of the spine
3. Never force a book open past its natural opening angle
4. Use book cradles or foam wedges for fragile bindings
5. Pencils only near materials — never pen or ink
6. Flatwork (maps, prints): handle with two hands, support
full sheet, never fold or roll unless already in that format
7. Photographs: handle by edges only, cotton gloves required
8. Transport: use book trucks with padded shelves, never stack
more than 3 volumes, never carry more than you can control
Shelving Rules:
- Books upright, snug but not tight
- Oversize volumes flat (never leaning at an angle)
- No bookends that press into the text block
- Pamphlets in acid-free pamphlet binders, not loose on shelves
Expected: All users and staff follow handling procedures. No new damage from routine use.
On failure: If damage occurs from handling, repair promptly (Step 4) and retrain the person involved. Most handling damage is cumulative — a single instance of pulling by the headcap won't destroy a book, but doing it daily will.
Step 4: Repair Damaged Materials
Perform conservation treatments matched to the damage level.
Repair Triage Matrix:
+---------------------+---------------------+----------------------------+
| Damage | Severity | Treatment |
+---------------------+---------------------+----------------------------+
| Torn page | Minor | Japanese tissue + wheat |
| | | starch paste (reversible) |
+---------------------+---------------------+----------------------------+
| Loose page | Minor | Tip-in with PVA adhesive |
| | | along inner margin |
+---------------------+---------------------+----------------------------+
| Detached cover | Moderate | Recase: new endsheets, |
| | | reattach cover boards |
+---------------------+---------------------+----------------------------+
| Cracked spine | Moderate | Spine repair with airplane |
| | | linen and adhesive |
+---------------------+---------------------+----------------------------+
| Foxing (brown spots)| Cosmetic | Do NOT bleach. Reduce |
| | | humidity to prevent spread |
+---------------------+---------------------+----------------------------+
| Brittle pages | Severe | Deacidification spray |
| | | (Bookkeeper or Wei T'o) |
+---------------------+---------------------+----------------------------+
| Mold (active) | Critical | Isolate immediately. |
| | | Dry in moving air. Brush |
| | | off when dry. HEPA vacuum. |
+---------------------+---------------------+----------------------------+
| Water damage | Critical/Emergency | Air dry within 48 hours |
| | | or freeze for later drying |
+---------------------+---------------------+----------------------------+
Conservation Principles:
1. REVERSIBILITY: Any treatment should be undoable without
damaging the original (use wheat starch paste, not superglue)
2. MINIMAL INTERVENTION: Do the least necessary to stabilize.
Not every old book needs to look new
3. DOCUMENTATION: Photograph before and after. Record materials
and methods used in the catalog record
4. KNOW YOUR LIMITS: Complex repairs (rebinding, leaf casting,
leather treatment) require trained conservators
Essential Repair Supplies:
- Japanese tissue (various weights: 3-12 gsm)
- Wheat starch paste (cook fresh or use premixed)
- PVA adhesive (pH-neutral, archival grade)
- Bone folder
- Microspatula
- Waxed paper (for interleaving during drying)
- Book press or weights
Expected: Damaged items stabilized using reversible treatments, with documentation in the catalog record.
On failure: If a repair exceeds your skill level, stabilize the item (wrap in acid-free tissue, place in a protective box) and flag it for professional conservation. A bad repair is worse than no repair.
Step 5: Store in Archival Materials
Replace harmful storage materials with acid-free alternatives.
Storage Material Standards:
+-------------------+---------------------------+---------------------------+
| Material | Avoid | Use Instead |
+-------------------+---------------------------+---------------------------+
| Boxes | Corrugated cardboard | Acid-free/lignin-free |
| | (acidic, attracts pests) | document boxes |
+-------------------+---------------------------+---------------------------+
| Folders | Manila folders (acidic) | Acid-free folders |
+-------------------+---------------------------+---------------------------+
| Tissue | Regular tissue paper | Acid-free, unbuffered |
| | | tissue (for photos too) |
+-------------------+---------------------------+---------------------------+
| Sleeves | PVC plastic (off-gasses) | Polyester (Mylar), |
| | | polypropylene, or |
| | | polyethylene |
+-------------------+---------------------------+---------------------------+
| Envelopes | Glassine (not all | Acid-free paper or |
| | archival grade) | Tyvek envelopes |
+-------------------+---------------------------+---------------------------+
| Labels/tape | Pressure-sensitive tape, | Linen tape (water- |
| | rubber bands, paper clips | activated), cotton ties |
+-------------------+---------------------------+---------------------------+
Special Format Storage:
- Photographs: individual sleeves, upright in acid-free boxes
- Newspapers: unfold, interleave with acid-free tissue, flat storage
- Maps/large prints: flat in map cabinets or rolled (face out) on
acid-free tubes (minimum 4" diameter)
- Audio/video media: upright, in jewel cases, cool and dry
Expected: All materials housed in appropriate archival-quality containers, free from acidic or harmful enclosures.
On failure: If archival supplies are beyond budget, prioritize the most valuable and fragile items first. Even placing acid-free tissue between a book and a cardboard box significantly slows acid migration.
Step 6: Plan for Disasters
Prepare a response plan for water, fire, mold, and other emergencies.
Disaster Preparedness Essentials:
1. PRIORITY LIST: Rank items for salvage priority (1-3)
- Priority 1: Unique, irreplaceable items (manuscripts, archives)
- Priority 2: Rare or expensive items
- Priority 3: Replaceable items
2. EMERGENCY SUPPLIES KIT (pre-positioned):
- Plastic sheeting and tarps
- Mops, buckets, sponges
- Fans (for air drying)
- Freezer paper and plastic bags (for freeze-drying)
- Flashlights and batteries
- Contact list: conservators, freeze-drying services, insurers
3. WATER EMERGENCY PROTOCOL (most common disaster):
- Stop the water source if possible
- Remove materials from standing water immediately
- Separate wet items: do not stack
- Air dry paper materials within 48 hours (mold starts at 48 hrs)
- If too many items to dry in 48 hours: freeze them
(-20°C stops mold, preserves for later vacuum freeze-drying)
- Interleave wet pages with absorbent paper, change regularly
- Never use heat to dry (causes warping and cockling)
4. DOCUMENTATION: Photograph damage for insurance before cleaning.
Record all affected items and their condition.
Expected: A written disaster plan, pre-positioned supplies, and a trained response team (even if the "team" is one person).
On failure: If a disaster occurs without a plan, the 48-hour rule for water damage is the critical knowledge: get wet materials air-drying or frozen within 48 hours. Everything else can wait.
Validation
- Environmental baseline established (temperature, humidity, light)
- Monitoring in place (continuous datalogger or daily readings)
- Handling procedures documented and followed
- Damaged items triaged and repaired or stabilized
- Harmful storage materials replaced with acid-free alternatives
- Disaster plan written with priority list and emergency contacts
- High-value or fragile items prioritized for preservation attention
Common Pitfalls
- Humidity neglect: Temperature gets all the attention, but humidity is the primary driver of mold, foxing, warping, and pest infestations. Monitor humidity first
- Irreversible repairs: Superglue, pressure-sensitive tape, and rubber cement permanently damage paper. Always use reversible adhesives (wheat starch paste, PVA)
- Over-handling during preservation: Ironically, zealous preservation efforts can cause more handling damage than benign neglect. Sometimes the best preservation is leaving an item undisturbed in a good environment
- Treating foxing aggressively: Bleaching removes foxing spots but weakens paper fibers. Accept cosmetic imperfections unless they threaten legibility
- No disaster plan: Most libraries that lose collections to water damage had no plan and no pre-positioned supplies. The plan costs nothing; the loss costs everything
Related Skills
catalog-collection— Catalog records should note preservation actions and conditioncurate-collection— Weeding decisions consider item condition alongside usemaintain-hand-tools— Tool care principles (clean, oil, store properly) parallel material care