I've been collecting Penman Sapphire alternatives for a while now and only recently got ahold of a real bottle of it. The inks I'm comparing it to are: Bungubox Sapphire, Diamine Blue Velvet, Private Reserve DC Supershow Blue, Noodler's Blue Eel, Noodler's Liberty's Elysium, Diamine Majestic Blue, a Noodler's mix from Fountain Pen Network called Noodler's Inkyman Sapphire (a 50/50 combination of Noodler's Navajo Turquoise and La Couleur Royale), and Montblanc BMW Blue. I've also included Private Reserve American Blue and Noodler's Baystate Blue for comparison but these aren't reviewed in as much detail. While I will focus on Parker Penman Sapphire I did include the other inks in my review page bellow.

Parker Penman Sapphire isn't a dry ink, but it certainly isn't a wet ink. It takes a fairly short amount of time to dry on Rhodia paper. It took fifteen seconds for Penman Sapphire to dry compared to twenty for DC Supershow Blue and over a minute (!) for Bungubox Sapphire. All the other inks performed similarly to Penman Sapphire. The lubrication is decent and the shading is reasonably high. The sheen is mostly moderate but if you manage to put a wet line down you'll get a very nice amount of red sheen on the edges of the line. By comparison, the sheen of Bungubox Sapphire covers the entire line in a soft pink hue. DC Supershow is very similar to Penman Sapphire as is Blue Velvet but with a more coppery coloured sheen. Majestic Blue is by far the biggest sheener out of these inks with a vibrant shiny-red sheen cover the whole line. None of the Noodler's sheen at all (apart from barely with Baystate Blue).

There is no feathering or bleeding from Penman Sapphire and the ink performs well on both Tomoe River and Rhodia. The feathering is also minimal on cheap copy paper as is the bleeding. Surprisingly DC Supershow performed slightly better on copy paper and but far the worst offender was Diamine Blue Velvet, closely followed by Noodler's Liberty's Elysium. Somewhat surprisingly the Noodler's Mix performed decently. Bungubox Sapphire performed well as expected and Montblnc BMW Blue performed the best.

Both the Bungubox Sapphire bottle and the Penman Sapphire bottle have internal reservoirs whereby you tip the bottle over (with the lid on) to fill it up. This is to assist when the bottle is nearly empty. While the Penman Sapphire works, at least, with the Parker Duofold International I have, I know that the Bungubox round bottle struggles to fill #6 nibs without having to tilt the bottle while filling. This is true of all sailor bottles with the internal reservoir. I believe they are removable, but I haven't tried as I expect it to be a messy and wasteful endeavour!