[Scribus] best image format

[heathenx]

During the conversion of my manual from InDesign to Scribus, I have noticed that InDesign handles 
the placement of PDF images a little better than Scribus. Let me fill you in. I use Autodesk 
Inventor to model our product, make a 2D print (3D isometric line art), and then save the 2D print 
out as a PDF. This worked well in InDesign because the PDF's didn't seem to degrade, in other words 
they kept their resolution when scaling up and down.

After a page was finished in InDesign, I would export the page out as a PDF file. This printed very 
well and looked very good in Adobe Reader. Scribus on the other hand prints pretty well but the 
finished PDF of the page looks very bad and takes a long time to render all of the images in Adobe 
Reader.

Instead of PDF files as my images, should I be using something else, like eps or tiff? I am using 3D 
isometric line art and I want the lines to be as crisp a possible when scaling the images up or down 
in an image frame.

heathenx