with polarized light microscopy (PLM) To collect a pigment sample for polarized light microscopy(PLM), "a surgical scalpel is used to collect a small scraping from a clean, representative area of paint in an unmounted sample. The tip of the blade is then pressed and pulled across a clean glass microscope slide, dispersing the pigment particles across the surface. The pigment is embedded under a coverslip using Cargill Meltmounts. The embedded pigments are then examined in cross and plane-polarized transmitted light with a Nikon Eclipse 8-i microscope from 200-400x. Digital images are captured to study the size, shape, and other morphologies of the paint sample." Fourier transform infrared spectrometry Fourier transform infrared spectrometry is a type of infrared spectrometry used to identify inorganic and organic components of compounds. It determines the "type of paint (chemicals, pigments, etc.) by analyzing the way in which its various components absorb infrared light." FITR is useful for historic paint analysis because it is "best used for the analysis of materials to aid in the choice of the optimum solvent needed to selectively remove certain coatings while leaving others unaffected." Portable spectrophotometer There are several factors that complicate the task of obtaining an accurate reading on a sample of paint. One of the most common arise from the variance in lighting conditions under which they sample is viewed, causing the color perceived to ‘shift’. This is perceptual shift can produce inaccuracies in ‘reading’ the paint sample under different lighting conditions, and cause what is referred to as a ‘metameric match’. To combat this disparity, conservators defer to the use of the spectrophotometer to obtain a more objective match. While conventional instruments were typically too large for transport, computer software now makes this technology portable, allowing for more accurate readings to be taken in situ. This is particularly useful in those instances in which paint samples cannot be readily transported to a laboratory, such as occurs when the substrate cannot be extracted nor transported, such as a metal gutter spout. Baty contends that “Computer software with the spectrophotometer allows colour matches to be made for all light conditions (daylight, domestic lighting and office lighting being the most commonly specified) and metamerism can be avoided, or predicted, if inevitable”. Using the Munsell Color System, the hue notation, the color, indicates the relation of the sample to a visually equally spaced scale of 100 hues. There are 10 major