Not every surface a part touches during printing is equally damaged
Support contact and bed contact leave very different marks. A face that touched support material usually shows visible witness marks, small nubs, or roughness where each support tip connected, and cleanup can tear or scuff the surface further. A face that touched the bed instead picks up a milder, more uniform texture from the build plate itself, generally a smaller cosmetic cost. This tool checks whichever face you designate as cosmetically important against both of these separately, across two orientation options.
How the comparison works
Each option is scored by whether the cosmetic face touches support material (weighted by your stated support tolerance) and whether it touches the bed (a smaller, flat penalty). The option that best protects the cosmetic face wins, with the alternative explained in terms of what tradeoff you would be accepting by choosing it instead, usually a support or strength consideration elsewhere on the part.
Worked example
A low support tolerance, cosmetic face up (no support or bed contact) versus face down (touches the bed, not support): face up wins outright here since it avoids both contact types, while face down is shown as viable only if some other orientation priority, strength alignment or overall support burden, matters more for this part than the bed-texture cost on the cosmetic face.
A common mistake
A frequent error is protecting the cosmetic face from support contact while forgetting that the same face can still touch the bed and pick up its own texture. Bed contact is generally milder than support contact, but for a truly critical show surface, avoiding both, not just the more damaging of the two, is worth the extra orientation effort.
Limitations
This protects the specific cosmetic face you name while showing the consequences elsewhere; it does not simulate your exact slicer's support generation, texture, or removal difficulty. Confirm the actual finish in a slicer preview and, for a genuinely critical surface, a test print.