Previously published theoretical analyses of manual methods of peak evaluation are summarized. Additional theoretical and experimental studies with idealized Gaussian peaks are reported for determination of peak area by triangulation, by planimeter, and by cutting and weighing. The triangulation method requires placing the base line, measurement of the peak height from the base line, and drawing the tangents and measuring the intercept on the base line. The indeterminate errors in the perimeter methods arise from placing the base line, tracing or cutting the peak outline, obtaining a reading, and, in the case of cutting and weighing, variability in paper thickness. The relative uncertainty in area for all three methods is dependent, as are the results previously reported for height-width integration, in part upon peak shape and in part on peak area. The relative error is generally greater for sharp peaks, and for flat broad peaks and for all peaks of small area. Minimum relative error is achieved for large peaks having a ratio of peak height to width measured at half height in the region of 1 to 4. Triangulation has little to recommend it. Cutting and weighing is vulnerable because of variations in paper thickness. Planimetry is less precise than height-width integration for peaks of small area but is comparable or somewhat better in precision for large areas.