Eight-page imposition with Preps-like surface identifiers
Imposition with Text-File-Based Marks 
 
Text File
Signature 1 <Sig1 text1 goes here>; <Sig1 text2 goes here>   Sheet 1 <Sheet1 text goes here>      Surface A <SurfaceA text goes here>         Page 1 <Page1 text goes here>         Page 4 <Page4 text goes here>         Page 5 <Page5 text goes here>         Page 8 <Page8 text goes here>         Page 25 <Page25 text goes here>         Page 28 <Page28 text goes here>         Page 29 <Page29 text goes here>         Page 32 <Page32 text goes here>      Surface B <SurfaceB text goes here>         Page 2 <Page2 text goes here>         Page 3 <Page3 text goes here>         Page 6 <Page6 text goes here>         Page 7 <Page7 text goes here>         Page 26 <Page26 text goes here>         Page 27 <Page27 text goes here>         Page 30 <Page30 text goes here>         Page 31 <Page31 text goes here>   Sheet 2 <Sheet2 text1 goes here>      Surface C <SurfaceC text goes here>      ...      Surface D <SurfaceD text goes here>      ...Signature 2 <Sig2 text1 goes here>; <Sig2 text2 goes here>...
The Resulting Imposition
For signature 1, sheet 1, surface A:

