In the intlay problem (Section 6.5), we mentioned that there were some subtleties in visualisation of Fastflo results in Encapsulated PostScript. Results shown on Fastflo's graphics screen are linearly interpolated between corner nodes of the mesh, regardless of whether the mesh consists of 3-noded or 6-noded triangles. If 6-noded triangles are used, the solution is given by a quadratic approximation and will generally be much smoother than it appears on the graphics screen. PostScript diagrams printed on paper through facilities on Fastflo's menu bar will display the correct degree of smoothness (linear or quadratic) in the solution.