Blood volume in carpet!
The following experiment was completed by releasing 50ml of blood into a carpet swatch. Excuse the color of the blood but it's getting old. Notice the blood almost looks black!
At first glance it dosen't look like much blood is here.
Flipping the swatch over reveals a much greater stain pattern. The bloodstain expert conducts experiments such as this to determine approximately how much blood was lost. The stain could in fact indicate that too much blood has been lost and that death probably occurred.