What is the difference between the two flex nibs?

Pro-Flex - Pros:

• Juiciness - It's fitted with professional calligraphy nib (the chrome Zebra G) giving you the greatest variance between thick and thin strokes, from hairline up to 2mm.
  
  
• Titanium Zebra nibs are available to buy separately on the site and last four times longer than chrome.

• Softer - it's a doddle to flex, requiring very little pressure.
  
  
• Ink Flow - The Japanese ebonite (a special type of vulcanised rubber)  feed delivers just the right amount of ink.

Cons:

• Maintenance - Before using your brand new pen, you will need to remove the nib, clean off any residual manufacturing oil, and re-install it into the housing before use. See how to do this here. You will also need to clean and dry your nib in between use, just like you would a regular dip pen, in order to prevent corrosion and prolong your nib's life.

• Replacing - because a calligraphy nib's raison d'être is to flex, they're made from alloys which are beautifully soft but can corrode and wear. So, just like a calligraphy pen you'll occasionally need to replace your nib (available here) when you notice your nib is no longer performing as well.
  
  
• Heat Setting - One of the tricks to getting the most from any flex nib is good contact between the feed and the nib. One of the clever things about ebonite is that it becomes malleable with heat, meaning you can achieve a super cosy fit for optimum ink flow. This process is called heat setting and I do it to every nib, but it can occasionally need re-doing if the pen is knocked etc. I'll be making a video to demonstrate this but a quick google will also give you a good number of explanations and videos demonstrating the process. If you're not confident about this I would recommend the Semi - Flex nib instead.
  
  
• Snag - The hairline nib when un-flexed creates beautifully fine strokes but, particularly if you're new to calligraphy, you will notice that it may sometimes snag on paper simply because it is so fine. For this reason we recommend using high quality paper with a smooth finish such as Bristol Board.

Semi-Flex - Pros:

• Maintenance Free - If you're not a calligraphy or fountain pen nerd and want a simple maintenance free writing experience, the Semi-Flex is the way to go.

• Durability - It's essentially a fountain pen nib (gold plated stainless steel) that has been designed to be make it more flexible so it will be more durable than the pro-flex.
  
  
• Smoothness - The Semi-Flex is an extra fine tipped fountain pen nib, which means that nib has an Iridium (super hard metal) end where it meets the paper.  This increases the durability of the nib and making it smoother to write with on a variety of paper types.  

Cons:

• Flex - Not really a con as it's still more flexible than 95% of the fountain pen nibs out there, but compared to the Pro-Flex it's not as soft and more effort is required to achieve a thicker stroke. 
  
  
• Hairlines - The pen is tipped which, as I mentioned before, increases durability and smoothness, but this means it can't achieve such fine hairline strokes as the Pro-Flex.
  
  
• Ink Flow - Flex nibs are inherently thirsty pens and require the feed to keep up and deliver ink to the nib so that it doesn't run out mid-sentence.  The Pro-Flex ebonite feed is the best in the world at delivering ink and is the main reason for the price difference between the two.  The Semi-Flex has a plastic feed which is good but due to lots of incredibly geeky factors can on occasion run out after lots of juicy inky flexing. It's easy to get it flowing again (by pushing more ink in using the included ink convertor) but it's worth considering before purchasing.

Can I keep ink in the pen between uses?

• By all means, all of the gold plated fountain pen nibs will not corrode. The Pro-Flex will corrode eventually but you can easily replace it, or prolong its life by flushing your pen with distilled water after every use and drying it. If you intend to leave ink in your pen between uses, be sure to use an ink with a neutral pH to avoid damage to the nib.  

What inks can I use in the Studio Fountain Pen? 

• The Studio Fountain Pen works beautifully with all fountain pen inks, I have a range of Tom's Studio inks (including shimmer!) You can find them here.  Be sure not to use calligraphy specific ink (or any type of acrylic ink) as this can clog the pen.
  

Good to know:

• We recommend you flush your Studio Fountain Pen pen thoroughly before use. This will remove any oils from the nib which are present during manufacture, and will impede ink flow. Any of the following are good options: our Nib Cleaning Solution, distilled water or water with a tiny touch of dish soap.

• The Pro-Flex nib is slightly different to a tipped fountain pen nib. When used fresh from the box, will take a little encouragement before it is performing optimally. Ink flow may be intermittent and railroading will be frequent - this is perfectly normal. Rest assured that after a page or so of writing it should settle in and start writing lovely and smoothly. 

• Every pen is machined from solid metals on a lathe used for making fine watch and aerospace grade components, so you can be sure your pen will write perfectly for years and years to come.

• We offer a complimentary repair service, so should your Studio Fountain Pen pen needs a little TLC please contact us.