Figure 3
Scatter-plot of the relationship between thickness and width on a logarithmic scale of the six projectile point types separately. The solid line is the least-squares regression line of the data points representing the mean values for each projectile point type. The gray area represents the confidence interval of the least-squares line. Projectile points with means in the upper left above the regression line display designs that maximize robustness, and points in the lower right below the regression line display designs that maximize penetration. The tip cross-sectional perimeter (TCSP) and work investment (WI) are also displayed in color gradient (values expressed in millimeters) and ball size, respectively. See Buchanan and Hamilton32 for a similar approach to explore effectiveness and damage capability.
