Blue Rivers

[Duke Speedy of Leighton]

I was going for a waltz...

[Big Insect]

Living in Bristol - we only have brown water to compare - either the muddy silt coming down the Avon to the Severn estuary or the tidal Severn (with a lot of red muddy silt washed down from the likes of the River Wye via Gloucester etc) that comes up the Bristol Channel & under the Suspension Bridge from the estuary at high tides.

Frozen Rivers are another fun project.
I once went to Beijing in the depths of winter - at a cool minus 27 degrees. The lake in the Winter Palace - a large contained body of water - had frozen completely solid, but as it had nowhere to expand to (as all the sides/banks/bottom were man-made stone walls) it had frozen into growing geometric pillars in the centre of the lake - where the water had been deepest and so froze the latest. It was like the Giant's Causeway in Northern Ireland - with the pillars thrust up from the surface in concentric rings some good 10 feeet high - not your flat as a mill-pond dutch masters frozen skating ponds scene at all.
The colour was also weird - a light turquoise blue in the depth of the ice, with frosty white on the surface. Plus the noise was unearthly - great creeks, cracking, groans and screaking - quite a spectacle.

I once made great blocks of floating ice for a river in a fantasy game - by pouring liquid plaster of Paris onto a plastic sheet and then shaking it free once the plaster had set - it created really realistic frozen chunks of ice to float down-stream.

[John Cook]

Why so many bright blue rivers on tables? To myself, just look odd.

I agree, bright blue for rivers just doesn't look right.  All my water is painted a dark blue/dark green/chocolate brown mix, blended and darker towards the deepest parts.  I then apply gloss varnish and if it is a pond, canal or similar I use Vallejo Still Water effect over the top.  This finds its own level and dries perfectly flat with a high gloss finish which reflects any natural light.  It is a compromise as it is impossible to replicate all weather conditions.  For rivers and moving water I do much the same thing  but I use the gel water effect which is much stiffer and allows you to simulate ripples and small waves.  Several layers gives an illusion of depth and a touch of white dry brushed on the peaks when dry adds to the illusions of movement.

I paint glazed windows black finished with a coat of gloss varnish.  You can't see much through windows from the outside unless there is back lighting and they appear black on most days.  The same applies to windows in vehicles.  The varnish reflects any available natural light.

I gave up trying to simulate aircraft canopies a long time ago.  They have light passing through them from all directions so you can see through them, often involve curves and convex surfaces, and what you see will be different depending on where the viewer is placed in relation to the aircraft.  That is too difficult to simulate effectively so I just paint them black with a gloss varnish too.  Those blue painted aircraft canopies with a yellow sun 'reflected' in them are completely over the top in my view and look completely unnatural.  
       

[Chris Pringle]

A reason not mentioned yet, I think - map convention? For a big battle game (as opposed to a skirmish), the tabletop is more akin to a 3D map than a diorama.

[DHautpol]

Returning to the practicalities of recreating our rivers etc..

I have gotten very attractive results painting with Miniature Paints "Umber" (number 86), and then brushing over with Mod-Podge.

[FierceKitty]

I was going for a waltz...

I think you're the luckier one.

[steve_holmes_11]

Aircraft canopies:

Mine are 1/600 scale, so except Heinkel 111, Focke Wulf 189 or B29 Superfortresses most areas of transparency are fairly small.
Advice at the time was to paint a pale blue (slightly darker on sides and undersides), then decide on the sun's direction and apply a tiny dot of white in that direction.

Vehicle windows:

GHQ suggested a gloss black then mark a horizon, with dark blue and paler hatching above this.

[Heedless Horseman]

Closed cab  vehicles... I would use an 'off black' / VERY dark gray. Open top vehicles are a problem but maybe a light gray. Military kit usually dusty / dirty... so, if you can work out where the wipers would clear... dusting around the cleared patch 'can' work... but very difficult to do well... have tried and failed in larger scales!