Awesome little filigree pen!  The Atome 1423/423 nib is excellent for fine-line filigrees…also fantastic for touching up letters, adding hairline flourishes to copperplate-style writing, and even works great for fine mono-line Spencerian and “Business Hand” style scripts.  You will find a million uses for it (well, maybe not “a million”, but a lot!).  :-). Problem with that nib, it is so small that it does not fit a standard straight holder.  There are other holders on the market that claim to work for this nib, but I bought one and it was garbage…did not hold the nib securely, and it “wobbled” around as I tried to write…totally unacceptable.  So I devised my own little holders that will hold that nib securely and “rock solid”.  Here is one of them…I made if from a gorgeous piece of durable acrylic so it will last forever if it doesn’t have an unforeseen accident.  :-). You need this!