A few sample files are included with FS Design Studio v3.5 in the \Projects folder including: ds_propdisk.bmp and ds_glass.bmp. The file ds_propdisk can be used to texture your transparent prop disks – just remember to assign a material (material name of “prop” for example).
The two bitmaps mentioned went missing from the FSDS 3.5 upgrade release (I don't know, but suspect that they're also missing from the "full" release).
Anyway, they will be uploaded to the Abacus site, but I've posted them at FFDS
