Thanks Hans. Sure, I've been doing this to generate the GraphViz diagrams etc plus hooking into various callbacks etc. What I don't yet quite understand is the correct navigation or link path to follow through the node structures and the best way to access or calculate glue (set) values for things like skip between words. All this reflects my currently hazy understanding of the liks + connections in the node graph. For example, see the attached PDF of the graph arising from a saimple example: \setbox0\vbox{Hello to Lua\TeX\ and another \vbox {here}} Even with this simple example the node traversal to render in the right order seems quite complex. Eg the TeX bit --- looping through the correct path to get the glyph order "TEX" For sure, you can work it out by following the graph, but what I'm interested to know is what the general case traversal algorithm would look like? Apologies for these fuzzy questions but this is early days for me with node traversal :-) Warm wishes Graham