The only way to confirm an acis object is a solid or surface is by going through the menu:
Modify-> Modify 3D Objects -> Create Surface or Create Solid.
You cant find out from the Selection Info or by right click on properties.

Id like to see the option available in the Selection info where youd know at a glance what type of object your dealing with.

In my installation that info is shown in the Selection Info palette. Always has been, for versions immemorial.

Henry H

Henry I put together a simple file in 2018pp so that I could explain what I mean, so Ive got two boxes and I must have changed one of them to a surface and left the other as a default box. Left the Part Tree active so that you can see what process I took. When the information is viewed in right click properties they are both reported as solids same for the DD. Whereas to learn what their real respective properties are I need to use the menu Modify-> Modify 3D Objects -> Create Surface or Create Solid. to learn what their base object is.

Maybe this should be in the Wish List, instead of FAQ.

The only way I can think of in the selection Properties Palette, is through Metrics - solid state, if it shows a volume its solid.   

As a workaround instead of messing with the menu.  Turn on the Solid/Surface toolbar.  Then you have a simple visual guide without opening menus.  Or possibly better, create a new toolbar, and put just the two solid / surface buttons on it.  then there is only two icons to look at instead of all five.   One just has to remember the object is the button which is greyed out, not active.

Genie can't make up her own mind as to what a "Surface" is.

Henry H

What's in a name?

The 'surface' is an ACIS solid of zero thickness/volume, as is a surface. 
So, Genie gets confused.

Personally, I never let it get me down! 

Regards Tim

Andy please move this topic to the Wish List, thank you.

Topic moved to wish list as requested.