Black Metalic Paint Sphere
This is from an environmental tapelift that was processed
with acetone. The paint vehicle in this case was soluble in
acetone. The result is a circular pattern of pigment and metalic flakes. The metalic
flakes in this case appear black because they are opaque.
Transmitted Crossed Circular Polarized Light
Definition/Function:
Significance in the Environment:
The presence of paint spheres indicates that painting has taken place at this locality
or nearby. Paint spheres persist in the environment and
are an indication of how thorough a cleaning has taken place since the painting event
and how extensively contaminants were dispersed in the
environment during the activities associated with the painting event. The presence of
paint spheres may indicate a source for solvent odors.
Characteristic Features:
Associated Particles:
Paint spheres are often found with other construction debris such as sawdust, plaster,
magnetite spheres, glass fiber, etc. In an automotive
body shop or vehicle maintainece facility they are often associated with paint flakes,
magnetite spheres, abrasives, tire wear, metal particles,
rust, plastics, glass fiber, cotton rag fiber, and clear, colorless spheres of
"clearcoat". If this is from a paint spray booth then spherical
agglomerates of alkaline salts, organic residues, and pigment may also be present. If it
is from a local uncontrolled painting activity then
the spheres will not be associated with construction, body shop, or water scrubber
residues.
References:
Crown, David A., THE FORENSIC EXAMINATION OF PAINTS AND PIGMENTS, Charles C. Thomas
Publisher, 1968.
