Slipstream is a very physical, even meaty painting. Macleod takes full advantage of the material effects of thick, undiluted oil paint to achieve a richly textured surface with a visual weight reminiscent of plaster or stucco. The paint is applied with a palette knife, resulting in thickly melded layers which give an almost sculptural effect.
The physicality of the paint enhances the artist's exploration of the human body but also generates strong symbolic effects. The form of the striding man is made palpable by the paint but the shadow forms echoing his body are equally dense. Macleod sees the body and its movement through space as equally important. A 'slipstream' is the invisible turbulence left in the wake of a physical entity moving through space. Macleod's densely resonating shadows suggest that where one has been is just as important as where one is going.
Other devices in the painting enhance this symbolic effect. The figure strides from left to right; given our tendency to read left to right, we see the figure as moving forward, into the future. The profile of the striding figure is reminiscent of evolutionary charts mapping the gradual development of a striding Homo erectus into Homo sapiens. This forceful, weathered figure appears to be both vulnerable and resolute, suggesting that Slipstream may also allude to the 'cycle of life' as an art historical subject. At a simpler level, the painting can be equated with outdoor activity-a hiker, or, more likely, a bather striding into the sea. In this way, the painting allows viewers to reflect on familiar recreational activity as well as larger, more metaphysical matters.