So, in conclusion, though the idea of a Japanese paper really appealed (it even had wispy, sun-on-the-sea-style highlights in it), I had to abandon the idea once I saw that the fibres made the ink spread in a bad way. Thus I used a heavy watercolour paper in the end, which was ideal in the end as I hand-coloured the back of the mackerel with a metallic turquoise glittery paint to add an extra dimension. (The weekend's photo will hopefully do more justice to that). Using an oil-based ink these days is not so popular due to the hassle and un-eco-friendly nature of the cleaning products, but in this case it was necessary to print then colour afterwards with watercolour. Something that you can't do obviously with water-based inks, as they will then run once you add further colour, post-printing, by hand. Oil-based printing ink with watercolour and metallic glitter paint on 250gsm smooth watercolour paper.