Scatter plots, bar plots box plots: Please use SigmaPlot, Origin, Grapher, IGOR Pro, or the free software tool gnuplot (http://www.gnuplot.info/). Avoid MS Excel for scientific graphs, as those graphs usually don’t look nice. In all cases avoid hairlines, all lines must have at least 1 px width. Hairlines can not be printed in a high quality printing process, because they are thinner than the printer's resolution.