Hello, frequent listener - first time caller etc. I've just started dipping my toes into dip pens (ho ho) and have made a discovery I thought I'd share (if this is common knowledge then just humour me). If you enter 'Wood Copperplate Calligraphy Pen' into eBay's search you'll quickly come across this.... It's a very cheap dip pen set from China - you get a wooden holder, three nibs and a tiny pot of ink. Well, it turns out that the reservoir attached to the 'Student Nib' pings off very easily and slides onto a regular G-nib with no fuss whatsoever! It holds a ton of ink and goes forever. I've ordered five more kits (a whopping £11) just for the reservoirs. As it happens the holders are comfortable and the 'Round Nib' is genuinely excellent to use so why not?. The reservoirs (the 'Round Nib' also comes with a reservoir) will probably fit other popular nibs, too, but like I said I'm new to all this so I can't check.