SarstedtPermanent Fine Tip Pen For Plastic Or Glass Tubes, Black (10 per pack)

I bought these pens hoping for something that would work better, last longer and hopefully not smear much, compared to the Sharpie® pens that we currently use. The claims made on this page were that they are fast-drying, smear and water proof, and permanent for plastic tubes. More importantly for me, the claim was made that they are also resistant to many chemicals and solvents. I was pretty excited to try something that might finally work for us. To test them, I performed the following experiment:I marked seven 13x100 borosilicate ("glass") tubes with the name of the treatment I would use, along with a patch of black scribble, and additionally stuck a piece of lab tape to each tube and wrote the name of the treatment there as well. Treatments performed included placing a small amount of each solvent onto a fresh Kim-Wipe and lightly rubbing the patch of scribble as well as the writing on the lab tape, or in one case, I just rubbed a bare-skin finger against the writing to see how it held up to skin oils. I left one control to which I did nothing. The solvents used follow:1) methanol2) reagent alcohol (90% ethanol, 5% each methanol and isopropyl alcohol)3) ethyl acetate4) HPLC-grade water5) skin-oil (bare-fingered rubbing)6) control (no treatment, for comparison)Additionally, I added ~5mL of water to another tube, placed it in the -80°C freezer for 45 minutes, removed it and let it thaw for 45 minutes.I then allowed the ink to dry for a few hours, just to make sure it was nice and set.Using a fresh Kim-Wipe coated with the appropriate solvent, against each tube I lightly rubbed both the scribble-patch and writing on the lab tape. I was very discouraged to see that the writing/scribble was instantly removed on each of the tubes to which non-aqueous solvent was applied. The tube rubbed with a bare-finger (to see how the ink would hold up to skin oil), the tube rubbed with a water-coated Kim-Wipe and the tube which was subjected to the Freeze/Thaw cycle and subsequently scrubbed with a clean Kim-Wipe (I did not wait for the condensation on the outside of the glass to evaporate) all looked good – pretty much the same as the control, to which I did nothingI went back onto Amazon and re-read the product description and saw that these pens were intended for use on plastics so I went back to the drawing board, and performed the same experiments on some small plastic (polypropylene) 1.5mL tubes, which we use to store aliquots of various things. Without exception, I got the exact same results. On the upper-side of each of the 1.5mL tubes is a small, translucent, “frosted” (as opposed to the remainder of the tube which is smooth and transparent) patch, which is where contents information is intended to be written. This patch also was tested and the results were consistent with everything else here.I took and attached a photo of the glass tubes (again, the plastic ones all had the exact same result, but the glass ones were more photogenic).These pens were over $30 when shipping was factored in! The only reason I gave this product 2 stars is that it works as described solely for water, skin oils, and survival of cryogenic temperatures. The ink itself also seems a bit darker, and better quality than the Sharpie® pens I’ve been using. But the writing from these pens did not “resist” any of the solvents I tried in any way, and the purported solvent resistance is literally the only reason I went with these guys. I’m not sure what the fellow reviewer who claimed “almost nothing will take it off” tried, but it most definitely didn’t hold up to my tests, which is unfortunate. I had high-hopes for this product.

I purchased these pens with the hope that the ink would not smudge off when handled with my bare hands. Our lab buys Sharpie Permanent Markers for writing directly on 2 mL centrifuge tubes, however, after several uses, the ink rubs off due to skin oils. To circumvent this I have to buy small stickers to write on and then affix to the tube. This is not too big of an issue, however I commonly write the tared weight directly on the tube. It is not uncommon for the mass to become difficult to read over time causing unnecessary work.Certain scientific companies sell smudge proof markers, but I have not found them as a 'fine tip.' In addition, they are quite expensive.Thus far I am very happy with the product. I will use these marker for writing on centrifuge tubes, Falcon tubes, and Petri dishes for cell work. I also work in a synthetic chemistry lab, but I would not expect this product to be stable against a host of organic solvents such as DCM, DMF, or acetone.In short, very pleased with the product.

What I needed

I initially tracked these down to write on a plastic ID card. The Sarstedt Permanent Fine Tip Pen worked perfectly.A few hours ago I encountered another use for this pen. I have a textbook with a very glossy cover. Since I am the forgetful sort of person who frequently leaves his texts behind, troubling his thoughtful colleagues who track him down to return them, I thought I would try writing my name on the cover. This particular paperback book has the sort of shiny cover that sheds ink like a puppy sheds water. I tried out my trusty Sarstedt pen, IMMEDIATELY wiped my finger over the ink after using the pen...no smudge!I am delighted.

I am a histology student so I need markers that were alcohol resistant for my cassettes and these came off during the staining process. Do not recommend now I have all these markers for an expensive price that I can’t use.

These pens are perfect for laboratory work. They write really well on tape, bottles, petri dishes, etc. They don't smear or rub off, and the pens write easily and smoothly on everyday items. They're high dollar, but buy them with a friend! It's worth the money for these fancy markers!

The Sarstedt pens I bought are Sarstedt pens.... that write really nicely.Best "sharpie" in the world!

Right upthere with my Mont Blanc pen, Cross. I found I kept hunting for this pen, will not write with anything else. I think I got hooked on this pen/marker. Four star because I have to recap it.andy.