A technique used for breads is to wash them down with very thin cornstarch/water slurry AFTER cooking it briefly into a very thin 'pudding'. You brush the bread with that slurry only for the last few minutes of baking. I think it is quite a common technique used by German bakeries.
Here you will find a picture of how the bread will look like.http://www.ploetzblog.de/2012/10/20/fre ... inkelbrot/
And the slurry has to be really thin; like 5g starch vs. 100g water (sorry, I have no idea how that 5% weight ratio would translate into spoons and cups)