Thanks Zachm, to my rescue yet again

! I'll give that a try later on, sounds easy enough. But first I must make some quick textures in Photoshop

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Edit: Just played around with that using some chequer maps. The only way to maintain a color gradient (like the original ramp) was to adjust the color gain for the different tones. Is there an easier way? That said, this way works fine if done carefully I guess.