Microscopy

Both stereomicroscopes and compound microscopes can be useful in analyzing materials. Using a compound microscope, components of an object such as individual pigments and fibers can be identified and characterized. Stereomicroscopy can be used when detailed analysis of surface features is necessary.

Microscopy: Analysis of a Photoreproduction

Comparison of these two photoreproductions under a stereomicroscope allowed the conservator to compare the line and ground quality of two items that had been identified as diazotypes based on visual inspection but demonstrated to be chemically different using FTIR comparison.

Microscopy: Analysis of a Drawing

The areas marked on the photograph indicate where samples of pigment and fiber were taken from the drawing. These samples were made into slides and analyzed using a compound microscope.

Using a compound microscope with polarized light capability, the sample pigment from this drawing was determined to be Madder lake, which is not extremely lightfast and should be shielded from excessive light.

Using a compound microscope with polarized light capability, the sample fiber from this drawing paper was found to be a softwood fiber, indicating that the paper is acidic and will discolor further and become brittle over time. Keeping the drawing out of light and in an alkaline environment, such as a buffered tissue wrapping or a buffered board folder, will prolong its life.

Microscope view of paper fibers and ink in a "v" shape
Photoreproductions Analysis: Sample 1

Analysis of Photoreproductions Using a Stereomicroscope

Photomicrograph by Melina Avery

Microscope view of paper fibers and ink in a "x" shape
Photoreproductions Analysis: Sample 2

Analysis of Photoreproductions Using a Stereomicroscope

Photomicrograph by Melina Avery

Verso of a Drawing by T.C. Cummings

Photo by Melina Avery

Fibers at 200x magnification at crossed polars
Analysis of an Unknown Fiber Using a Compound Microscope

Photomicrograph by Melina Avery

Pigment at 400x magnification under transmitted light
Analysis of an Unknown Pigement Using a Compound Microscope

Photomicrograph by Melina Avery