Acetate: An acidic plastic that causes photographs and
documents to deteriorate and fade.
Acid: A substance that produces hydrogen ions when dissolved
in water. Acids have a pH of less than 7.0. Acid is
produced in paper when the paper and papermaking chemicals
in the paper deteriorate, or when acid is absorbed from
its environment. Over time, acid breaks the paper fibers
down, causing the paper to deteriorate and become brown
Acidic: A term used when something contains acid or
has a pH level lower than 7.0.
Acid Free: A term describing materials with a pH value
of 7.0 or higher. Note: Materials with a pH level of
7.0 are neutral and those with a pH level greater than
7.0 are alkaline.
Acid Migration: The transfer of acid from one acidic
material to another less acidic material, either by
direct contact or by absorption of acidic gases from
the surrounding atmosphere.
Adhesive: Any substance that allows two or more surfaces
to adhere to one another.
Alkaline: A term used when something contains alkali
or has a pH level of more than 7.0. It is the opposite
of acidic. In paper products, an alkaline substance
is added to the pulp during the manufacturing process,
which gives permanence and durability.
Archival: Originally the term "archival" meant that
a material or product is permanent, durable, or chemically
stable and that it can therefore be used safely for
preservation purposes. No standards exist that describe
how long an "archival" product will last.
Buffer: An alkaline substance-generally calcium carbonate
(CaCO3)--added to the paper to make it acid free.
Buffered: A term used in the paper industry designating
that an alkaline filler has been added during
the paper making process, which makes the paper
acid-free. It also increases the smoothness of
the paper surface, improves brightness and opacity,
and helps prevent ink from feathering.
Calcium Carbonate (CaCO3): The primary filler
added in the paper making process that makes paper
Cardstock: A general term for heavier papers frequently
used in scrapbooking.
Chlorophenal Red: A chemical that indicates the
pH of paper (or if the paper is acid free).
Colorfast: A pigment or dye that is resistant
to environmental exposure, such as light, acid,
heat and other atmospheric conditions.
Cropping: Altering the boundaries of a finished
photograph by trimming or masking the photo.
Deacidification: An alkaline-salt process that
raises the pH level in paper. It impregnates the
paper with a high alkaline reserve and neutralizes
existing acids while preventing the development
of future acids.
Digital: A process that uses numerical digits
to create a uniform picture on a computer.
Digital Camera: A camera that created a photograph
in digital form.
Durability: An item's ability to resist the effects
of wear and tear from use.
Dye: A colored substance (which is soluble) that
is added to ink, paper and textiles. Generally
speaking, dye colors are not permanent enough
to be used for fine-art applications where long
term lightfastness is required.
The silver-gelatin image layer of processed film.
Encapsulation: A safe process for protecting valuable
newspaper articles and other paper documents.
Hand tinting (hand coloring): The process of applying
colors with oils or dyes to the surface of a black
and white photograph, giving it the appearance
of a colored photograph.
Humidity: The measurement of the moisture content
Lightfast: A term describing a material not affected
or faded by sunlight, fluorescent tubes and lighbulbs.
Lignin: The substance that gives plants and trees
their strength and rigidity, and also binds wood
fibers together. When wood is broken down to make
paper, the lignin becomes unstable. Paper that
contains large amounts of lignin, such as newsprint,
is very acidic and will turn yellow when exposed
to light and humidity.
Lignin Free: To be considered lignin free, paper
can contain a maximum of one percent lignin.
Migration: The transfer of chemicals to neighbouring
materials. An acidic paper can make an item next
to it acidic because the chemicals migrate.
Mylar: An uncoated, clear, polyester plastic made
by Dupont. It is chemically stable and does not
release harmful gases. Mylar D is used in sheet
protectors and photograph sleeves, and is safe
Neutral pH: The center reading of 7.0 on the pH
scale of 0-14. It is neither acidic nor alkaline.
For manufacturers, the acceptable pH neutral range
Non-bleeding: A term that describes an ink that
does not spread from the original mark on the
Opaque: Any substance or surface that will not
allow any light to pass through.
pH: A measurement of the degree of acidity and
alkalinity. On a scale ranging from 0-14, pH 7.0
is neutral, above 7.0 is alkaline (or acid free)
and below 7.0 is acidic. The scale is logarithmic
progression, meaning 6.0 is 10 times more acidic
that 7.0. pH can only be measured on water-soluble
Note: The letters "pH" come from the French words
for "hydrogen power".
Permanent: A term describing materials that are
chemically stable. Permanent materials are not
prone to deterioration. Pigment: A dry, powdery
agent that possesses color. A pigment will not
adhere to a surface, so a binder is required to
unite the pigment to the paper. A pigment does
not dissolve in liquid and does not fade when
exposed to light.
Polyethylene: A flexible, chemically stable, naturally
slippery plastic with little tendency to cling.
It is normally manufactured without anti-block
and slip agents. Polyethylene is used primarily
in the manufacturing of photographic sleeves and
Polypropylene: A clear, pliable, chemically stable
plastic used in manufacturing of photographic
sleeves. Polyvinyl acetate (PVA): A plastic with
properties that cause photographs and documents
to deteriorate and fade. Note: The pH-neutral
glue called "PVA" which is commonly used for book
binding and box making, is not suitable for use
Polyvinyl chloride (PVC): An unstable plastic,
generally called "vinyl" and "Naugahyde" that
may exude oily plasticizers or emit corrosive
and acid hydrogen-chloride gas. It is easily identified
by its strong plastic odor. Do NOT use sheet protectors,
binders, photo enclosures, corners or any other
products made from vinyl with your photographs,
negatives or memorabilia.
Preservation: The act of stabilizing an item from
deterioration by using the correct methods and
materials designed to maintain the conditions
and longevity of the item.
Pulp: A wet slurry of fibers and water that is
the basic ingredient of paper.
Ream: A ream is 500 sheets of paper, regardless
of the paper size or thickness.
Red eye: The bright pink or red color that can
appear in the pupils of people or animals pictured
in a photo when the flash is used.
Sepia: A brownish color produced on photographs
in the photographic process.
Solvent: A substance that dissolves another substance
to form a solution. Water is a solvent for sugar.
Water Soluble: A substance that dissolves in water.