These are the two Rotring Isograph technical pens that I bought recently. They are the 0.5 and 0.7 tips.
I was actually looking for the Rotring Rapidograph technical pen but it's not sold here in Singapore. With the pens in hand now I can say that I prefer the Isograph because it's easily refillable as compared to the Rapidograph which uses cartridge. I think it's more economic to just get a big bottle of ink than to keep buying the Rotring pen refills.
I'll be reviewing the Rotring technical pens in a separate more detailed review soon.
These are technical drawing pens so they produces uniform lines without variations. It doesn't suit everyone's drawing style of course.
The pen below them is the Pilot Hi-Tecpoint which is also one of my favourite pens. I've sandpapered off the surface, as I do with all my Hi-Tecpoint pens — it's easier to see how much ink is left in them. I've also refilled it with the waterproof Rotring ink.
They are all strapped to the handy Accurasee case.
Here are more pictures.
That's a 23ml Rotring ink bottle. They also sell the 250ml big bottle.
You can disassemble the Rotring Isograph for cleaning.
This is what the drawing tip consist.
These are the sizes in comes in.
They are sold separately and in sets.
Here's an attractive set to get at www.amazon.com/gp/product/B001G7PDM6