Bokeram

Today buckram is a stiff cloth, usually cotton but sometimes linen or poly-cotton blend.

Medieval bokeram or bougran seems to have been something different. It was often supple enough to use for flags, banners and pennons:

..X pièces de bougueran dont furent fais lesdiz petiz penonceaulx (Comptes Lille L., t.1, 1413-1415, 95).

In ij ulnis de bukram emp. pro j baner, 2 s. 2 d. (c1400) Mem.Ripon in Sur.Soc.81 132:

Bokeram for penouns..v 3erdis and a half of grene bokeram, iij s. (1426-7) Rec.St.Mary at Hill 64:

It was also suitable for lining clothing:

[Lined with] sendale, bokerames, samytes.  (1351) Doc.in Riley Mem.Lond. 267:

To bey apese of blak bukram for to lyn with a gown for me. (1463) Paston 4.76:

...IX pièces de bougrains pour doubler les robbes de camelot (Comptes roi René A., t.2, 1478, 82)

It was also used for coat armor and jousting arrays:

j. cote d’arme de bocram Cardiff Records 58

...les princes joustoient en parures de drap de laine, de bougran (LA MARCHE, Mém., I, c.1470, 268).

It was listed among toilles, which seem to have been cloths of vegetable fiber, typically linen, but including cotton and hemp. The Dictionnaire du Moyen Français defines it as linen cloth.

. . ...toutes autres toilles tainctes comme bougrans, futaines de toutes sortes, sarges et sayettes (LA VIGNE, V.N., p.1495, 262

It was usually, but not always, colored: black, green, blue, red, yellow, and purple:

Þe queade riche þet zuo ofte ham ssredeþ ase of to zofte bougeren and of to moche of pris pourpre. (1340) Ayenb.(Arun 57) 258

xx virgarum de nigro bokeram pr. x s. (1409-12) in Gras Eng.Cust.Syst. 688

j silour de blewe bokram, cum quertons de eodem. (1415-1416) Will York in Sur.Soc.4 382

...XX aulnes de bougran bleu (Comptes roi René A., t.2, 1453, 8)

But sometimes it was white or uncolored:

Item, une autre coultepointe de bougran, blanche, pointée bien menuement, et à plusieurs bestes de poincture de mesmes. (Invent. mobilier Ch. V, L., 1379, 392). Couvertures d'autel. Premièrement : Une vieille couverture de veluiau, pallée de roys rouges et vers, et est doublée de bougran qui est destaint. (Invent. mobilier Ch. V, L., 1379-1391, 151)

If bokeram was typically a colored cloth, probably linen or another vegetable fiber, how do we reconcile this with the difficulty medieval dyers had in producing colorfast tints on linen? Perhaps the the frequent use of bokeram as a lining fabric is part of the answer: in this application it would have little exposure to direct sunlight.

It was also used as hangings within churches, where direct sunlight may have been less threatening, as well as vestments:

i white cloth for the high auter, with a crosse of blew bokeram. (1447) Doc.in HMC Rep.3 App. 316

...toute la nef de l'eglise estoit toute parée de soye et de boucran aux armes de monseigneur de Bourgoingne (LA MARCHE, Mém., III, c.1470, 62)

Albæ viii de serico..alba una de bukeram, cum parura brodata. a1300(1222) Reg.S.Osmund in RS 78.2 132

It was also used for beds and bed canopies:

Y wol she have a wurstede hangyng and bed of blak bokeram. (1444) Will Daubeney in Som.RS 19 341

A bed of burdealexander..a spavore of blew bukreme. (a1500) Collect.Anglo-Premonst.in RHS ser.3.6 264

Here are the entries in the Dictionnaire du Moyen Français, The Anglo-Norman Dictionary, and the Middle English Dictionary