Evidence sent for analysis

The details of what is required in a Photo log and paint deposit.

What must be sent

Paint samples and photo logs are analyzed when there is either inconsistent hit and run damage or a disputed collision.

To aid in the analysis, the following evidence must be sent:

  • Photo log(s) of the vehicle damage.
  • Paint sample deposit(s).

Photo log

The photo log is studied in conjunction with study of the recovered sample to make the best use of the evidence. Relevant photo evidence for analysis includes

  • the textural features of the contact zone
  • the deformation profile, and
  • other factors recorded photographically.

Paint deposits

Depending on the type of claim, the engineering firm will analyze different things.

Type of Claim

Paint deposit

What is analyzed

Inconsistent hit and run

From claim vehicle only

The factors which help distinguish the paint deposits as either automotive or non-automotive are

  • complex layer structure characteristic of auto paint systems
  • relative hardness of automotive paint top-coat, and
  • high resistance of auto paint to certain solvents.
Important: Minimum alteration of the paint deposit is important because it can affect the layer structure and the relative hardness.

Disputed collisions

Matching assessments of questioned deposits against the alleged second vehicle paint system.

Parameters compared are

  • pigment
  • layer structure, and
  • metallic particle morphology.

Important: When the denying vehicle has suspect damage, the comparison sample must be from the immediate area and panel because re-spray and flexible bumper cover paint can give different panels slightly different characteristics. Small fragments only are needed, when full thickness is present.
Note: Chemical analysis is rarely an asset because of the extreme complexity of paint composition.