Museum Water Emergency Response and Recovery

Response

The focus of the response stage will be on moving non-wetted inkjet prints out of harm’s way, preparing a suitable response and recovery workspace, retrieving the wetted inkjet prints from the water-affected environment, removing them from enclosures, rinsing dirty or salty prints, and freezing if necessary.

The working environment during a water emergency will be chaotic and complex and we cannot emphasize enough how important it will be to make as many decisions as possible during water emergency planning. Still, while the disaster plans developed and written before the event will be crucial in providing a general framework for response and recovery, the truth is that every water emergency will be unique and both spontaneity and flexibility will be key. A quick assessment of the extent of any water emergency will be vital and should include identifying the number of collection spaces affected, the number of inkjet prints wetted and by what type of water, the number of non-wetted prints and where these might be moved to safety, the amount of flat surface available to immediately air-dry wet prints, and if not enough, how many prints will need to be frozen, where to freeze, and finally whether any prints will need to be bathed to remove excess debris or reduce soluble contaminates.

To support responders during water emergencies affecting inkjet prints, IPI has created a one-page quick guide, which is free for download (PDF). It outlines the most basic and effective approach to water emergency response for inkjet prints and aims to be accessible to anyone. Laminating or placing it in a sealed sleeve will protect it during use in an actual emergency. Keep copies of this guide with and/or near inkjet prints in the collection.

Below is additional information for each of the steps outlined in the one-page guide. It is anticipated that this information will be used primarily during planning and training as opposed to during an actual water emergency affecting inkjet prints.

Remove Non-Wetted Inkjet Prints from the Affected Area

The first step should be to salvage the non-wetted inkjet prints from all of the affected areas. In even the worst water emergencies, some objects will have remained dry. Unfortunately, these dry prints may have been exposed to the elevated relative humidities that water emergencies often create. Relative humidities above 65% can result in ink bleed, changes to print surface qualities, bonding of prints to each other or enclosures, and mold. For this reason, inkjet prints must be moved to an area of lower humidity as soon as possible.

Spaces to store dry inkjet prints removed from a water-affected area should be preselected during the disaster planning process. It is possible, however, that adjustments may have to be made if the event is large and widespread enough to have inundated areas originally expected to be safe. In addition to spaces within the facility, it is possible that spaces in other buildings or nearby institutions may have to be utilized, though transport can add another set of logistical problems and additional handling risks. Remember that simply moving inkjet prints to higher shelves within the affected area will not adequately protect them.

If necessary, temporary storage areas with RH above 65% can initially be used for the dry materials to buy time and mitigate the greater risks associated with keeping them in the water-affected spaces, but prints should not stay under those conditions for long. The table below shows the number of days before inkjet dye migration will begin to show. If the RH of the affected area is 75% RH, then prints must be moved out within 7 days. If the RH is 80% or above, they should be moved out immediately.

Note that the table applies only to dye inkjet prints or mixed dye/pigment prints, as pigment-only prints will not bleed at high RH. But when in doubt, move them out. Additionally, IPI’s dew point calculator can be used to determine the amount of time before mold germination begins at various elevated relative humidities. Mold risk will apply to both dye and pigment inkjet print types, because mold affects the substrate. The dew point calculator can be found at http://www.dpcalc.org.

IMPORTANT: While inkjet prints may be stored temporarily in an elevated humidity environment, they cannot be dried there. Inkjet prints can only adequately dry at humidities below 65%. An inkjet print left for an extended period above 65% may eventually feel dry to the touch, but will not have released enough moisture to prevent continued ink bleed, changes in surface sheen, blocking, and/or mold.

In addition, handling accidents during recovery can put non-wetted inkjet prints at risk of becoming wet and potentially destroyed. The response environment can be chaotic and attempting to move large amounts of materials very rapidly can result in knocking objects off shelves or inadvertently toppling stacks. Therefore, responders should be instructed that speed of object removal (for wet or dry materials) will not significantly increase success compared to a slow and orderly process. In addition to human error, there is also risk of shelving collapse due to water weakening of the shelving materials or the increased weight of soaked collection items. These are risks for both the collection objects and the responders and each should be explained to those involved in the recovery.

Prepare a Response Workspace

Prior to removing wet prints from water-affected areas, a safe workspace should be established to separate prints from their housings, bathe dirty and/or salty prints, drain excess water, and prepare prints for freezing, if necessary. Again, potential locations should be identified during the disaster planning and preparation process. If prints have been immersed in dirty or salty water, they will need to be briefly bathed in clean water to remove excess debris and any easily solubilized substances (see more on this step below). The chosen area should be equipped with resources for these activities including for the largest print sizes that may be encountered.

Enough surface space to lay out prints to air dry will ultimately be needed and locating such spaces before removal of prints from the wetted environment is important. This space must be below 65% RH to prevent continued damage and mold growth. If such spaces are unavailable, freezing wet prints may be required. Since some prints may be too large for available freezers, including those provided by professional recovery vendors, the largest prints should be prioritized for air-drying, while the smaller ones are frozen.

Remove Inkjet Prints from Water

When the task of removing objects from the affected environment has finally begun, caution must be taken to reduce the risk of further damage to materials while handling. Wet prints are heavier and more fragile than dry prints and therefore are at a much greater risk for tearing under the increased water weight. Always lift and carry the print from underneath with an auxiliary support that extends beyond all the edges of the print by at least an inch. This will help responders avoid having to touch the inkjet prints while carrying them, as their surfaces will be significantly more sensitive to abrasion and scratching. There will also be greater chance for smearing dye and pigment ink colorants.

It is important to remember that inkjet-printed images are not true photographs, which were designed to withstand wetting during processing. This means that while many guides for water emergencies state that photographs can stay submerged for up to 48 hours, this does not apply to inkjet. They must be removed from water as soon as possible.

Remove Wet Inkjet Prints from Enclosures

Do not allow inkjet prints to dry inside enclosures. Paper enclosures may absorb colorants from the print face and fibers from the paper can become embedded in the print’s surface. In the worst case, the paper can permanently bond to the print. Plastic enclosures trap water inside prolonging wet time, causing colorants to continue bleeding, print surfaces to ferrotype or block, and mold to grow.

On the bright side, prints inside of enclosures may be partially or even completely dry despite the outside of the enclosure having been fully inundated with water, but responders must be careful not to drip water from wet boxes or prints onto these dry prints as they are removed from their housings or frames.

If inkjet prints are to be frozen as part of the salvage process (see below), they may not need to be removed from individual enclosures. This has the benefit of reducing the amount of handling the wet prints will be subjected to; however, the enclosures will also take up valuable freezer space.  Decisions about whether to remove prints from housings, such as envelopes or sleeves, before freezing will have to be made on the spot based on freezer space, staff availability, and the prints’ inherent susceptibility to handling damage.

Bathe Dirty or Salty Inkjet Prints

If the offending water was clean, then bathing will be unnecessary and would likely exacerbate problems. Prints that have been exposed to water containing contaminants such as salt or sediments may require bathing to reduce soluble substances and easily removable debris. These inkjet prints should be gently bathed in clean water. Tap water is fine for this step, but water under pressure, such as directly from a tap or hose, should not be used. This bath should be as brief as possible as prolonged washing will not improve outcomes and may cause further irreparable damage. The aim of bathing is not to clean the print, but purely to dilute that which is readily soluble, as well as remove larger particulates.If particulates do not immediately release from the print’s surface, a soft brush can be used to gently dislodge them while the print remains immersed; however, be very careful not to abrade the print surface. Cleaning of stains should be delayed until after drying, so energy can be focused on salvaging as many additional prints as possible. Some contaminants can be harmful, so gloves should be worn. In extreme cases, health hazards may be significant enough to warrant immediate and proper disposal of soiled objects. Such decisions should be made in consultation with emergency first responders.

Remove Excess Water

After prints have been retrieved from water, and bathed where necessary, any excess water remaining on the print surface needs to be removed. There are two important reasons for this. First, it speeds the drying process as the volume of water that must be evaporated is significantly reduced. Second, it limits the damage to the objects because as long as prints are wet, even after being removed from water, they continue to deteriorate until their moisture content has sufficiently dropped.

When retrieving inkjet prints from relatively clean water, or when rinsing has been completed, the best approach to removing excess water is to slightly tilt the print and allow it to run off. To complete drying, however, inkjet prints should be kept completely horizontal as colorants may run over time.  Never attempt to wipe water from the surface of an inkjet print as that can smear the image or abrade the delicate surface layers. Some inkjet types can be safely blotted but others will be destroyed, so only perform this technique under expert supervision. Excess water can also be removed by wicking. Holding an edge or corner of a highly-absorbent paper in any pooled water can draw it safely up and away from the print’s surface.

Recovery

The focus of the recovery stage will be on managing the drying process for the wetted inkjet prints. This may include immediate air-drying or freezing for later drying when enough space, materials, and staff are available to manage the thawing process safely and effectively.

Air-Drying Inkjet Prints

Air-dry inkjet prints individually, horizontally, and face up on fiberglass screens or blotter paper. Non-absorbent, non-porous surfaces can extend drying times. The drying environment must be below 65% RH to avoid continued colorant bleed and mold growth. Tactile assessments of dryness will not suffice, as it is possible that an inkjet print can feel dry but still have enough internal moisture to foster mold growth. Instead, the chart below should be used to predict the time to fully dry. Do not stack, rehouse, or return inkjet prints to storage until fully dry. Note that very large inkjet prints may take additional days to dry.

Do not attempt to air-dry inkjet prints stacked with interleaves of any type, such as blotter paper, newsprints, polyester weave, etc. Stacked inkjet prints, with or without interleaving, will take longer to dry resulting in further damage, including additional colorant loss, alterations to surface sheen, transfer of paper fibers from interleaving into the print face, permanent bonding to interleaving materials, and mold growth.

Freezing Inkjet Prints

If there are not enough staff, space, or material resources to safely air-dry all prints immediately, then freezing will be needed until adequate resources are available to thaw and lay the inkjet prints out individually and horizontally for drying. Note that freezing is not as safe as air-drying and minor additional damage may occur; however, it will prevent mold growth, which is a more serious problem.

Determine the volume of freezer space available, keeping in mind that freezers should not be densely packed, as doing so will significantly hamper the rate of freezing. If there is inadequate freezer space available onsite then seek help from nearby institutions or commercial facilities that can handle and freeze prints safely. A commercial water emergency recovery vendor may be needed when water events are very large and exceed the staff and other institutional resources needed to safely and effectively respond (see sidebar above).   

Remove prints from boxes by carefully cutting the corner joins to allow the box walls to fall open. Inkjet prints in envelopes or sleeves may be frozen in those enclosures, and this can help minimize potential handling damage. Given the large sizes and potentially heavy weight of saturated window mats, it will likely be better to separate these prints before freezing. If the wetted prints are not in individual housings or have been removed from housings, interleave them with wax paper slightly larger than the prints around all edges. Bag the prints in sealable polypropylene or polyethylene bags to avoid dripping water inside the freezer. Only bag prints in groups small enough to manage during the thawing process. There should be adequate airflow around the bagged prints to hasten freezing. While standard freezers will be sufficient for small numbers of prints, blast freezers will reduce temperatures quicker when there are larger numbers or more densely packed prints. Prints too large for the freezers should have priority for air-drying.

Thawing Frozen Inkjet Prints

Inkjet prints that have been frozen eventually need to be thawed. Always work on a clean, dry surface. Do not remove and work on more prints than can be addressed within a workday, or that exceed the amount of flat surfaces available to individually and horizontally air-dry them all. Do not allow prints to thaw inside the sealed bags. Remove prints from bags immediately and then begin to separate from enclosures and stacks as soon as thawing allows. Waiting any longer than necessary to separate from the enclosures or wax paper will result in additional damage to prints, especially dye prints where the wet colorants will continue to bleed. Be aware that the center of the stack will thaw slower than the edges, and larger prints take longer to thaw than smaller prints, so be patient. Lay the separated inkjet prints out individually, horizontally, and face up on fiberglass screens or blotter paper. Use the time-to-air-dry chart above to determine drying times once the prints have reached room temperature.

Post Dry Handling

A final warning should be made. Prints that have been wetted and dried will be different in many ways than they were before the water emergency, even if they look unchanged. The many subtle visual changes that can occur include alterations in surface texture or sheen, shifts in color density and hue, paper darkening, etc. In addition to these, there may be changes that make the objects more fragile and therefore in greater need of sensitive handling after recovery. These will mostly relate to the papers’ specialized layers that received the ink during printing. These layers may now be embrittled and more prone to cracking or delamination and can be more sensitive to abrasion and scratch. Greater consideration may be needed when providing access to and during handling of these objects in the future. It may be worth creating study or exhibition surrogates for any inkjet print that has shown even the slightest indication of increased fragility. Certainly, housings that are more robust and the use of auxiliary supports when handling will provide additional protection. Finally, adding notes about this increased risk to the catalog records and any conservation documentation for these materials will be helpful to everyone needing to physically interact with the objects in the future.