On of the common sights on the NSWGR back in the 60's was the use of coal hoppers for wheat traffic during bumper crops.
This adds some visual variety to the look of a bulk wheat train, having a few tarped wagons amongst the normally covered roof wheat hoppers.
This is a feature that I definitely want to reflect so I have had a go at making some tarps to go over a couple of Trainorama HCH Hoppers.
I've heard of some people using aluminium foil to make their tarps, and some using tissue or paper to make them, so I thought I'd try to combine the two and see how it worked.
My reasoning for using both is that the aluminum foil gives the tarp some strength and the ability to be molded and hold its shape, while the single layer of tissue paper would give it the texture it needs, as well as readily accepting paint.
I took a sheet of normal cheap aluminium foil, and using a wide artists brush thinly spread on it a diluted mixture of PVA glue, and then layed a single layer of tissue over it and allowed this to dry overnight.
Using some cheap water colours bought at the $2 shop I mixed up a watery mix of grey/brown and using a little bit at a time gradually built up the colour of the tarp using slightly different shades to break up the uniform monocolour look.
Once dry the tarps were cut to the correct dimensions, bent into shape to represent how it would look with a ridge pole beneath it and placed in on top of the hopper to see how it looked. Normally two tarps would be used with each one wrapping around the ends of the hopper, so the picture is an illustration of the texture and colour of the tarp only, not the completed look of the model.
It's possibly a little too dark overall, however I have seen some pictures of very weathered and darkened tarps, especially on wagons pulled behind steam engines. Overall though I'm quite happy with the texture and general look of the tarps, and now have to figure out how to add the tie down rings to the hopper and add ropes holding the tarp down.