Suzanne,
Most of the collage makers I use give me the option to do outlines or not do outlines.
Peggy,
FWIW, I use Zoner Photo Studio as my primary DAM and front-line Editor. I switched from Lightroom to Zoner several years ago. Yeah, I still pay for Lightroom & Photoshop and I also have ON1, ACD, Luminar, PSP, and some others, but I prefer Zoner and use it whenever possible. The collage feature is just a bonus.
Cheers