Inspired by muzz64's Mini Floor Stands I thought I'd make something similar but customizable in OpenSCAD.
Each of the four lines of text can have their own size (and font/style in OpenSCAD but not Customizer) but I'd say 6pt is the largest size to correctly space. You don't need to define each line of text if you just want say two lines.
To help with dual extrusion I've made it so you can show only the text/border (white bits in demo image) or just the sign, or everything and Customizer will create multiple STL's - see slicer screenshot.
Added a Makefile so you can run
make PART=sign to get openscad to generate the STL.
For different messages on each side see my other design
FlashForge Creator Pro 2016
So far tried PLA and dual-extrusion PLA+ABS (tip: never try to get ABS to stick to PLA!)
Doesn't need a raft or supports. You can either paint/sharpie the border/text or pause and change filament or dual extrude.