by Lord Thomas the Black



            Welcome back to another edition of Blackmaille! This month, I'm going to go over my recent experiments with a method of rustproofing mail armor: oil blackening!

            Some time back, I saw a shirt dated @ 1560 in the "Treasures of the Czars" exhibit when it came to Topeka, KS. This mail hauberk had a hard black finish on it, as if it had been lacquered. Modern repairs stood out on the black surface, since they'd been made with brass butted rings. I took all the notes and sketches I could, and contacted the museum to try to get more information on how this had been done, but to no avail. Then, some months later, I found the answer on the Armour Archive ( ). A fellow by the name of Jason Grimes had blackened a piece of mail using plausibly period techniques, and his results were exactly what I had seen in the museum.

            This article will consist of the notes I made while experimenting with these methods. Special thanks go to Jason Grimes, Cet, and Stephen of Forth Castle for their help on this project through their advice on the Armour Archive.



1 can "Pam" olive oil cooking spray

1 bottle 100% pure olive oil

1 sm. Spray bottle

1 12" x 18" cookie sheet

1 "Kingsford" BBQ Bag

1 metal spatula

1 old paintbrush

1 outdoor grill


The Original Instructions (such as they were)

Set oven for "Broil"

Set temperature for 400 degrees

Coat mail on one side with oil, cook for 30 minutes

Turn, coat other side, cook for another 30 minutes

Let cool

Wash off excess oil

            After receiving my new tools for making riveted mail, I made four test patches, one for each combination of medium and heat: spray/oven, spray/grill, oil/oven, and oil/grill. Here's what happened.


Oven test, Side 1

            On the cookie sheet: left patch (L) was squirted with oil, right patch (R) was sprayed with cooking spray.

            Oven was set to "broil" at 400 degrees.

            Cookie sheet was set on middle rack of oven.

1100        Experiment started. Mail placed in oven.

1110        Some light gray smoke noticed. No big deal, as I was told that the oil would smoke a little.

1115        Cat started freaking out, so I went to let her out. Upon return, noticed black smoke pouring out of oven. Opened oven to find mail on fire. Shut off oven, put out fire, aired out house, examined mail:

L - Very oily black coating with flecks (probably from extinguisher).

R - Even black coating, a little flaky.

             Suspect mail might have been a little too close to the heat source; also, probably too much oil used. Spray bottle nozzle discarded in favor of old paintbrush. No damage evident to oven, so experiment continued.


Oven Test, Side 2

             L - Olive oil brushed on with paintbrush

             R - Olive oil cooking spray applied with can held back further from sample.=

            Oven set to "broil" at 400 degrees.

            Mail placed on bottom rack of oven.

1130        Mail placed in oven. Silent prayer said in hopes of not burning my apartment down this time.

1145        No smoke visible from outside of oven. Good sign. Visual inspection of mail shows some light smoke, no flames.

1200        After 30 minutes, still no external smoke visible. Visual inspection reveals mail has stopped smoking. Cookie sheet removed and set on cooling tray.

 1230        Inspection of mail shows oiled mail is still speckled, even without extinguisher. Sprayed mail is a nice, uniform black. Must wash samples after mail cools.

 1300        After cooling, samples were washed with "Dawn" anti-bacterial dishwashing detergent and warm water. All oily residue removed.

L - Oiled sample is ugly. Specks are still evident. Coating is thick, but appears brittle, as it has chipped off in several places while washing.  

R - Sprayed sample is a nice, uniform black. Coating is smooth and even. No flaking evident after washing. More durability tests needed.

             So far, cooking spray on the bottom rack of the oven seems to be the best method. Must give credit to "Cat Lassie" for letting me know something was amiss.  After a week's handling, oiled sample exhibited more chipping and flaking, especially on burnt side, while the sprayed sample is just as evenly blackened as always.


Grill Test

           You may notice that the header doesn't say "Side 1". There's a reason for that. The grill test didn't go as I'd hoped. On with the notes…

            L - Olive oil brushed on with paintbrush

            R - "Pam" olive oil cooking spray

             Outdoor grill (not burning down my kitchen again!) loaded with "Kingsford" brand "BBQ Bag" (no lighter fluid or kindling needed).
             Exact temperature unknown.

 1545        Lit off charcoal bag.

 1550        Oiled/sprayed samples and placed them onto grill.

 1605        After 15 minutes, flipped both samples and stirred coals. Results not promising, as both samples very oily-looking still. Perhaps heat/height of
             flame insufficient?

 1606        Oiled sample fell into coals. Have notified next-of-kin.

 1607        Sprayed sample followed oiled sample into coals. As sample was an orphan, no next-of-kin were notified.

 1608        Fire (open flames) have died down, so hot coals were raked over samples. Rest of experiment conducted with samples in the fire.

 1620        Both samples removed from fire. Coals still very hot. Results discouraging, as both samples appear light gray in color. Unsure if this is due to
             ash, or if oil has burned off altogether. Will know more when samples have cooled and have been washed.

 1630        Packed up experiment to go inside and wash samples.

 1645        Both samples washed, and the results are in:

L - Unevenly blackened, with the oil being burnt off altogether in places. Both sides are even in that the uneven blackening appears on both sides regardless of which side was actually oiled in the first place. All the rings appear somewhat darker, but not black, to the extent that the oven samples are black. Whether this is the result of a thin blackened coating or just the rings having been heated remains to be seen.

R - This sample is in much the same condition. The only way to differentiate the two, in fact, is to note that this sample is still nearly completely bare wire on the side that wasn't directly sprayed. Again, the rings are slightly darker on the sprayed side, leading me to believe that it's a thin blackened coating. Since the oil is almost completely burned off, however, it's hard to tell.

             Obviously something went horribly wrong with this side of the experiment, and I suspect it was a combination of not enough heat being applied directly to the samples, and the samples having fallen into the coals. Much more research and experimentation will be necessary to produce the desired results with this method.

             To sum up, it appears that the oiled sample did marginally better on the grill, while the spray was better suited for the oven. While the oil over an open flame was the most period method, it didn't produce the results (in this trial) that I'd hoped for. Perhaps more trial-and-error will change that. For those of us in the Current Middle Ages, however, the cooking spray/oven method offered the best combination of simplicity, cost-effectiveness, ease of handling, and even, durable results. Just be sure to keep your piece that you're blackening far enough away from the heating elements in your oven!


UPDATE: It’s now been over a year since I first conducted these experiments, and the sprayed sample in the oven still has not shown any sign of rusting. This is even after being handled almost constantly for a month straight, being left outside on the ground in the rain, and repeated handling by patrons at the Kansas City Renaissance Festival. I’ve decided that while this is the least “period” (in terms of materials and techniques) of the methods I’ve used, it’s definitely the most maintenance-free, and looks the best, so this is what I intend to use on all of my riveted maille projects. Anyone interested in what this finish looks like should ask me at the Baronial meetings, or write and I’ll take photos.

            As always, thank you for joining me for another (unusually long) edition of Blackmaille. Any questions, comments, suggestions, or research on that whole "oil/grill" thing should be sent to:

                                    c/o Tom Beckett
                                    6112 E 126th St, Apt 104
                                    Grandview, MO 64030

            Next month: Japanese mail

             See you next month!


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