Rohrer&Klingner Ink sketchINK,Thea' 50ml

This works well and operates well from a fountain pen which means that sketches can take place at any moment.

Love this! Flows smoothly and lovely colour. I have used it with my Lamy Safari fountain pen and it works great! It is also waterproof which is great when doing line and wash sketches.

My favourite ink for sketching, either with a fountain pen or brush. Waterproof once dry.

Nice ink but I'm not sure if it clogs pens or not. My fountain pens seem to dry very quickly and the flow is sometimes slow and blocked. But never tried other inks to compare. Otherwise it dries in paper quickly and is waterproof. Nice black but not super deep black. I think I'd like to try another ink brand once finished to compare as the clogging is a little annoying.

I love the colour and it flows well. Do not leave it in a pen that is not in use for a period of time or it may clog the nib.

I was hoping for a grey ink, which is what the description says. However if you look at the picture, it depends on the time of day, or the weather of something else as to what colour I get. All this scribbles were done in the space of 5 minutes with this ink. First time I used it, it seemed more brown so I used something else. Grabbed it today and tried on test bit, and the grey was perfectly grey. Then used it on my sketch and it turned brown again (which is not good news for my drawing). So I tried it on the scrap and this time it was brown. I have shaken the bottle, stirred it, spent ages trying to make sure it is mixed well, but it tends to be more donkey brown than the grey I thought it was.

A brown component settles out of the ink and requires vigorous shaking to re-combine it. the sediment can be seen at the bottom of the bottle. Problem is the ink separates in the pen reservoir which is much more difficult to re-combine with the possibility of this sediment clogging the pen. Not recommended.

Nice ink to write with however this is not waterproof. I left it ten minutes but it still ran when I used a damp brush on it with both water and watercolour paint. I shook the ink before use as advised, and used it on watercolour paper, but even though it seemed dry it just dissolved when liquid was added. No idea why but I will be returning it.