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CHARACTERISTICS OF METAL

good conductors of heat good conductors of electricity are ductile/malleable high tensile strength usually lustrous/shiny atoms of most metals have few electrons in their outer energy level most metals are solid at room temperature insoluble in water they lose electrons high melting point

characteristics of wood

CHARACTERISTICS OF WOOD

Sapwood:Sapwood is the wood that conducts water and nutrients (sap) vertically in the tree. The higher

the moisture content in the sap, the more likely checks (cracks) and splits will occur in thewood. Sapwood ranges in color from cream to light tan. It readily accepts stain and helps to

create character in finished wood projects.

Heartwood:Heartwood, the column that supports the tree, is sapwood that has lost its conductivity. It gives

the tree its strength and often contains rich colors, depending upon the specie, because ofchemical additives (extractives) in the cell walls. Heartwood is relatively dense and will shrink

very little. It does not accept much stain, yet it contributes to beautiful contrasts in wood

projects.Growth Rings:Growth rings are annual, and they consist of springwood and summerwood. The cell walls in

springwood are thin and porous. The pores are large to aid in the movement of water.

Springwood readily accepts stain. Summerwood (aged springwood) has thicker walls and smaller

pores and helps to establish the grain pattern. It does not accept stain as readily as

springwood.Ray Cells:

Ray cells conduct horizontally and help to control shrinkage in hardwoods because they act asrestraining rods that control expansion from the center. They radiate outward from the center of

the tree and form into stacks of flattened tissue bands. Tissue bands in hardwoods, though small

in number, can pose real problems because they (if present) are planes of weakness thatcontribute to v-shaped splits (checking), honeycombing, and fissures. When cut, the end fibers

may split and cause the wood to absorb excessive stain. This can result in very dark places in

the finish of a wood project. Ray cells are very fine in softwoods and, therefore, do not present

conspicuous problems.

End Grain:All wood used in projects will have some end grain. As with ray cells, fibers in end grain may

split and absorb excessive stain.Grain Defects:

Defects in wood grain can be caused by environmental factors that can lead to twisted grain(spiral); interlocking grain such as that found in sycamore; knots that can star-check or crack;

compression wood (in conifers) which pushes a branch against the pull of gravity; and tension

wood (in hardwoods) which pulls a branch up.Spalted Wood:

Spalted wood is caused by fungus, a living organism, that obtains its nutrients fromliving wood cells. Unchecked, fungus will destroy the wood. It also poses health risks to

wood workers who do not take the proper precautions.

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CHARACTERISTICS OF PAPER

There are several terms that are often misused in describing paper. Durability, for example, is often confused with

permanence, formation with grain, and finish with surface. Understanding the applicable terms will greatly improve your

chances of getting what you want when buying paper.

Acid-free is a term used to indicate that a paper or board, when it leaves the factory, has a pH of 6.5 or higher, which

indicates that there is little or no acid that can accelerate aging or deterioration. However, "acid-free" does not mean

that the paper or board is guaranteed to remain in this condition or that it is free of any other undesirable chemicals. It

also does not mean that it is safe to use the paper or board for archival storage or framing. "Acid-free" is a label

sometimes used in misleading ways by a few manufacturers to imply permanency when it does not exist.

Conservation is the repair, restoration, and preservation of documents, objects, and artwork with the intention of

preserving them permanently.

Deckle refers to a wooden frame used in the papermaking process and to the irregular edge on the paper produced by

the use of that frame. In papermaking, a screen or mould is passed through a suspension of pulp to form sheets of

paper. A deckle is a separate wooden frame fitted over the papermaking mould to prevent excess pulp from spilling over

the mould as it is lifted from the vat. A deckle edge is formed when a small amount of pulp seeps under this frame,producing an irregular edge on the paper. This deckle edge is often left untrimmed. Handmade papers have four deckle

edges because each sheet is made individually and the water is allowed to drain from the mould in both directions.

Mouldmade papers have two deckle edges and two torn edges because one continuous sheet is formed and the water is

allowed to drain in one direction. The one long sheet is later torn into smaller sheets, which accounts for the two torn

edges.

Durability is the ability of a paper to retain its original qualities under use. Most print papers, for example, do not have a

durable surface and will be ruined by erasure, but bristol paper is very durable because it will maintain its surface

qualities under repeated erasures. Durability does not necessarily indicate permanency. The American Society for

Testing and Materials defines durability in their publication ANSI/ASTM D-3290 as "the ability of a paper to resist theeffects of wear and tear in performance situations. For example, paper currency should be made durable, but

permanence is not a problem."

Fillers include such materials as kaolin (clay), calcium carbonate, and titanium dioxide, which are used to fill the pores on

the surface of papers and boards to make a paper whiter and more opaque, as well as to give bulk. The more filler that is

used, the less fiber there will be, and it-is the fiber that maintains the strength of a paper or board. Today, it is becoming

increasingly common for manufacturers to load up ground-wood boards with calcium carbonate to buffer them against

the significant acidity that develops as the relatively unrefined pulp ages. Too much of this chalk will result in a great

sensitivity to changes in humidity, which can cause severe warping. If such a board gets wet, the chalk dissolves and the

board can easily fall apart.

Finish is the condition of the surface of a

CHARACTERISTICS OF GLASS

- Solid and hard material

- Disordered and amorphous structure

- Fragile and easily breakable into sharp pieces

- Transparent to visible light

- Inert and biologically inactive material.

- Glass is 100% recyclable and one of the safest packaging materials due to its composition and properties

Glass is used for architecture application, illumination, electrical transmission, instruments for scientific research, optical

instruments, domestic tools and even textiles. Glass does not deteriorate, corrode, stain or fade and therefore is

one of the safest packaging materials.

These properties can be modified and changed by adding other compounds or heat treatment.

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