On my fully updated desktop and laptop Tumbleweed computers. In gwenview when I
select Plugins > Images > both Print Images and Print assistant are greyed out.
The File > Print function does work, but I cannot set the picture size. - It
fills the page.

Current versions of packages installed:
gwenview5         17.12.1-1.1
kipi-plugins       5.8.0-3.1
libKF5Kipi32_0_0  17.12.1-1.1
libkipi-data      17.12.1-1.1

In Digikam: Tools > Print Creator... does bring up a "print assistant" dialog
box, and I am able to select number of prints per page etc.

Mark