Mikrosil
Definition
Brand-name silicone polymer casting compound (also Microsil, AccuTrans) used to lift a fine-detail negative of a tool mark from the scene without damaging the original. Captures sub-micron striations.
- Material type
- Silicone polymer casting compound
- Common brand names
- Mikrosil, Microsil, AccuTrans
- Application
- Negative cast of a tool mark at the scene
- Detail capture
- Sub-micron striations
- Effect on original mark
- Non-destructive
Common questions
Why cast a tool mark instead of only photographing it?+
Photography flattens three-dimensional striated detail into a two-dimensional image and loses depth information; a silicone cast preserves the actual surface topography, allowing later direct microscopic comparison against a suspect tool rather than comparison of two photographs.
Why is silicone preferred over harder casting materials like dental stone?+
Silicone remains flexible after curing, so it releases cleanly from undercuts and irregular surfaces without breaking or distorting fine striations, and it shrinks minimally during setting, both of which preserve the sub-micron detail a hard material would risk losing.
Related terms
- AFTE Range of Conclusions
- Association of Firearm and Tool Mark Examiners standard scale: Identification, Inconclusive (A, B, C), Elimination, Unsuitable for examination. The same scale used...
- Class Characteristic
- A feature shared by an entire group of objects (every shoe of one model has the same sole tread; every tire of...
- Combination Mark
- Both impressed and striated features in the same mark, typical of pry-bar and chisel attacks where the tool first bites into the...
- Impressed Mark
- Also called indented or compression mark. Tool is pressed perpendicularly into the softer surface and reproduces the contour of the tool's working...
- Individual Characteristic
- A characteristic unique to a specific typewriter unit arising from manufacturing variation or service wear; used to identify or eliminate a specific...
- Striated Mark
- Also called scratch, abrasion or scrape mark. Tool slides laterally across the surface and leaves parallel striations from microscopic imperfections on the...
- Subclass Characteristic
- Batch-level feature introduced by manufacturing-tool wear that is shared by a sub-population of tools made in the same production run (a die...
- Toolmark
- The microscopic striations and impressions left on a softer material (a bullet, a cartridge case, a lock body) by contact with a...