EFNIR: Robert Oster Deep Sea

[LizEF]

Extra Fine Nib Ink Review: Robert Oster Deep Sea

This is review #352 in my series. Here's the YouTube video:

Post-recording notes: This ink was gifted to me by a generous FPGeek.  The ink is green or maybe green-teal - it's hard to say. The darkness of the ink sometimes makes it hard to see the sheen. Also, sheen only tends to show when my pen is flowing wet. The video doesn't show it, but this ink is like a very dark version of Diamine Steel Blue.

Cleaning was easy with plain water, but expect to do several flushes - the dye is very concentrated.

Errata: The word "Nib" is missing... I missed an end quote - grr.  It was important enough that I doctored it into the still images and video.  Also: "...the below averagE lubrication that's making it seem a little drieR..." (the cheepies in my rain gutters were distracting me!)

NOTE: The map of the Wizardlands has been updated. (See the link below for The Adventures of Quin and Makhabesh.)

Zoomed in photo (Very close, but the dark spots in the image aren't as dark in person. (Those spots are sheen.))

Screenshot (The text is far too dark. Go by the scan!)

Scan of Completed Review (This is closest. It might be a tiny, tiny bit more teal in real life (I'm having trouble deciding).)

Absorbent Paper Close-up (top is puzzle paper like thick newsprint, bottom is old 20lb copy paper) (Both show fairly accurate color.)

Line width (The "I" in "Ink:". Magnification is 100x. The grid is 100x100µm. The scale is 330µm, with eleven divisions of 30µm each. The line width for this ink is roughly 321µm. With 352 inks measured, the average line width is 298µm.) (The color is deceiving - to my eye, it was very green. I could also see a lot more sheen.)

Microscope image (400x (both images).  Different areas on the slide. :))

Other (Sorry, capturing the sheen on this one was hard, but the "7" "t10"s and "1230" show it. Pink cat stamp available at JetPens. ;))

Previous Review: Koh-I-Noor Document Blue.

Images also available on Instagram: @zilxodarap.

Want to influence the inky sequence? Take the "next ink" poll.

View a list of my inks, complete with review results in a google sheet.

Need to catch up on The Adventures of Quin and Makhabesh? Find the whole story here.

Hope you enjoy. Comments appreciated!

[Sailor Kenshin]

Holy neurons and jellyfish, Batgirl!  And is that red sheen I spy on that green microtree?

 

Let me thank you in advance, @LizEF, for reviewing an ink I never saw before, and the thtory.  🐍 Holding my breath, figuratively, for Etthri.

 

I have Emeraude de Chivor and had a sample of Yama Dori.  I don't know… but I suspect the colors are not for me, handsome though they are.  You always manage to make it (and each Tuesday) magically fun.  🎉 👏🏻 💝

[LizEF]

3 minutes ago, Sailor Kenshin said:

Holy neurons and jellyfish, Batgirl!  And is that red sheen I spy on that green microtree?

  Well, there's definitely a pinkish-reddish sheen, so yeah, that's probably what you see in both micro-images.

 

4 minutes ago, Sailor Kenshin said:

Let me thank you in advance, @LizEF, for reviewing an ink I never saw before, and the thtory.  🐍 Holding my breath, figuratively, for Etthri.

You're most welcome!

 

6 minutes ago, Sailor Kenshin said:

I have Emeraude de Chivor and had a sample of Yama Dori.  I don't know… but I suspect the colors are not for me, handsome though they are.

These are colors that appeal to me when I first see them, but that I tire of easily.  A fill every few years will do.   I prefer the paler version in Diamine Steel Blue that's more cheery and summery - that I can enjoy for a good long while before moving on.

 

8 minutes ago, Sailor Kenshin said:

You always manage to make it (and each Tuesday) magically fun.  🎉 👏🏻 💝

Thanks!

[yazeh]

Great review @LizEF .

This is one of those tricky colours, that I used to think I liked but don't. Interesting how in the screen capture the two last lines are turquoise.  

 

But who cares Ethri is back.  !

Will it be in "Thearch for Profetther Eenneth,"  or "The Profettor who came in from the Cold" . 

 

Thanks for bringing magic, inky joy to this cool summer day. 🙏🙏🙏

[inkstainedruth]

@LizEF -- Too teal-leaning a green for my taste.  But thanks as usual for the comprehensive review!

Ruth Morrisson aka inkstainedruth

[LizEF]

31 minutes ago, yazeh said:

Great review @LizEF .

Thanks!

 

31 minutes ago, yazeh said:

This is one of those tricky colours, that I used to think I liked but don't. Interesting how in the screen capture the two last lines are turquoise.

Yep.  I know what you mean - love it on screen, tire of it quickly in the pen.  I suspect that by the time we got to the bottom, the pen was writing a little drier and that changed what we see in the image.  (Also, probably, uneven lighting.)

 

32 minutes ago, yazeh said:

But who cares Ethri is back.  !

Will it be in "Thearch for Profetther Eenneth,"  or "The Profettor who came in from the Cold" . 

  Tune in next week!

 

32 minutes ago, yazeh said:

Thanks for bringing magic, inky joy to this cool summer day. 🙏🙏🙏

You're most welcome!

[LizEF]

7 minutes ago, inkstainedruth said:

@LizEF -- Too teal-leaning a green for my taste.  But thanks as usual for the comprehensive review!

You and your wallet are most welcome!

[yazeh]

15 hours ago, LizEF said:

You and your wallet are most welcome!

Maybe you need to introduce a character as Ruth's wallet.

 

[LizEF]

1 hour ago, yazeh said:

Maybe you need to introduce a character as Ruth's wallet.

  No, a sentient coin purse (aka wallet) named Ruth.  She keeps you from wasting your money on things you really don't need and distracts would-be thieves by telling them cat stories!

[yazeh]

43 minutes ago, LizEF said:

  No, a sentient coin purse (aka wallet) named Ruth.  She keeps you from wasting your money on things you really don't need and distracts would-be thieves by telling them cat stories!

That would be even better. Maybe professor Eenness' wallet is that, and she/it his, when professor Eenness went to cold for new ink. 

[LizEF]

1 hour ago, yazeh said:

That would be even better. Maybe professor Eenness' wallet is that, and she/it his, when professor Eenness went to cold for new ink. 

[Baggins]

Teal with Sheena Easton. Not really my kind of music.

loved the review though.🎼🙉🩵

[LizEF]

50 minutes ago, Baggins said:

Teal with Sheena Easton. Not really my kind of music.

  Maybe it's with Charlie Sheen and it's not your kinda movie...

 

50 minutes ago, Baggins said:

loved the review though.🎼🙉🩵

Thanks!

[inkstainedruth]

7 hours ago, yazeh said:

Maybe you need to introduce a character as Ruth's wallet.

 

Given that we're going to have to have some water pipes in our house checked and maybe replaced, and then have repairs done to the living room and front hallway ceiling and the wall between the living room between the living room and hall?  The wallet is already taking a beating....

Ruth Morrisson aka inkstainedruth

 

ETA:Oh, and add to that?  Earlier this afternoon I had to go pay the school taxes -- which are higher than the county and town property taxes COMBINED....    And the really scary part is that I paid the "early bird" discount amount at that....

[yazeh]

1 hour ago, inkstainedruth said:

  

1 hour ago, inkstainedruth said:

Given that we're going to have to have some water pipes in our house checked and maybe replaced, and then have repairs done to the living room and front hallway ceiling and the wall between the living room between the living room and hall?  The wallet is already taking a beating....

Ruth Morrisson aka inkstainedruth

 

ETA:Oh, and add to that?  Earlier this afternoon I had to go pay the school taxes -- which are higher than the county and town property taxes COMBINED....    And the really scary part is that I paid the "early bird" discount amount at that....

We the collective of FPN wallets, wish yours to be strong, and full of nice crisp bills, and no bills to pay. 🙏🙏🙏

[InesF]

What a blast¹! I didn't know how much I missed your EFNIR ink reviews. Thank you so much, @LizEF!

This is the first of your reviews I read after the break. I stop here for now, because I have to read all the other summer-EFNIR reviews first ...

 

R.O. Deep See is an ink with interesting colour, almost a must have. Thank you again, @LizEF, for adding one more to my list of inks to buy ...  

 

 

 

 

^{1) For an unknown reason 🤭, the description of the magic laboratory reads somehow familiar. Such a pity, Professor Eenness is missing ... 😳}

[LizEF]

5 hours ago, InesF said:

What a blast¹!

...

^{1) For an unknown reason 🤭, the description of the magic laboratory reads somehow familiar. Such a pity, Professor Eenness is missing ... 😳}

The secret to descriptions in books is to suggest and let the reader's imagination fill in the details!

 

Welcome back!  So glad you've returned in time for the rescue of your fictional self!

 

5 hours ago, InesF said:

I didn't know how much I missed your EFNIR ink reviews.

Thank you!

 

5 hours ago, InesF said:

Thank you so much, @LizEF!

You're most welcome!

 

5 hours ago, InesF said:

This is the first of your reviews I read after the break. I stop here for now, because I have to read all the other summer-EFNIR reviews first ...

 

5 hours ago, InesF said:

R.O. Deep See is an ink with interesting colour, almost a must have. Thank you again, @LizEF, for adding one more to my list of inks to buy ...  

You're most welcome!

[inkstainedruth]

On 8/27/2025 at 5:40 PM, yazeh said:

  

We the collective of FPN wallets, wish yours to be strong, and full of nice crisp bills, and no bills to pay. 🙏🙏🙏

Well, as a slight (very slight) plus, there was some sort of EMS activity around the corner from me the other night (fire engine, ambulance and two police cars) and when I went out to see what was going on, I found a five dollar bill on the sidewalk in front of my house (makes a nice change from the litter that people seem to think is perfectly okay to leave for us to pick up... ).

OTOH, a friend called my husband yesterday, and a mutual friend was having to clean out the place of a deceased person that I think had been a co-worker of hers.  And the friend who called said that there was a leather recliner for $300....  And my husband is seriously interested (the current recliner -- not sure where that one was originally from it's been in the living room so long -- supposedly "on its last legs"...).  Frankly, I'd much rather be spending money on a replacement mattress and box springs, since the current ones were bought 25+ years ago....

Ruth Morrisson aka inkstainedruth

[yazeh]

@inkstainedruth I like the nuance. The wallet is happy for once, the bank account not so.

I tend to agree with you, about the mattress dilemma. Though, if I base myself on  American sitcoms, it seems men spend most of their lives watching sports, while eating. Now what if change the recliner for a stationary bicycle.

 

[LizEF]

13 hours ago, inkstainedruth said:

Frankly, I'd much rather be spending money on a replacement mattress and box springs, since the current ones were bought 25+ years ago....

59 minutes ago, yazeh said:

I tend to agree with you, about the mattress dilemma.

I just ordered a new mattress.  They're painfully expensive (or the decent ones are, anyway).  Hopefully it proves worth it - my ancient one has been leaving me with a sore lower back (until I get up and get moving) for a couple years now - good for preventing me from lounging in bed, bad for a good night's sleep.  Oh the dilemma.

 

56 minutes ago, yazeh said:

Now what if change the recliner for a stationary bicycle.

Nope, has to be a treadmill - it forces you to keep walking.  As soon as the "rider" slows down / stops pedaling, a stationary bike is just an uncomfortable chair...   (Or you can get one that pedals for you, but that kind of defeats the purpose - may do some good, but not much.)