I'm inserting a still image (png file) as a clip. I'd like it to display for 12 or 16 seconds since it contains text that I'd like people to be able to read.

It seems there is a five second limit. Is this so?

I tried to just stack three copies together but there's a flash of white between clips. What is the recommended way to work around that?

Which Kdenlive version are you using? Recent Kdenlive versions (0.7.5 and maybe 0.7.4) allow you to extend your image clip as you want. If you have an older version, the maximum image duration is defined in "Settings"->"Configure Kdenlive", you will see a field called: Default duration, image clips. Change that duration, and re-add your clip, then you can have an image clip that is longer.

However, I would recommand an upgrade if you can

I'm on 0.7.5

the problem was I was attempting to do it in the project monitor area, not the timelines.

got it now...

too darn simple for my "looking for complexity" brain.