Hi,
Not knowing why you chose Nylon but I would like to suggest an option that I have not seen mentioned on these posts which is.. HPL (High Pressure Laminate) aka Trespa.
It is a dense (usually Black) resin/paper material (think, very thick Formica) which comes in board form (up to 3 x 4m) with thickness's from 6-14mm. You have probably come across it in Public Toilets as the cubicle walling and doors. It is possible to get it on Ebay for between £10-£20 psm second hand. It is also used to clad modern buildings (screening). Generally with a paint finish to both sides.
It is very rigid and machines very well.. (Routers are best) holds thread very well and because it is formed with heat and pressure is much less brittle than cast plastics like acrylic.
I consider it to be a viable alternative to Aluminium for frame building though I think I would get shot down for my impudence from the elders..