I accidentally found this information from the Wikipedia page Boiled leather:
The word cuirass for a breastplate indicates that these were originally made of leather.[11] In the Late Middle Ages, the heyday of plate armour, cuir bouilli continued to be used even by the rich for horse armour and often for tournament armour,[12] as well as by ordinary infantry soldiers. Tournaments were increasingly regulated in order to reduce the risk to life, and in 1278 Edward I of England organized one in Windsor Great Park at which cuir bouilli armour was worn, and the king provided swords made of whale bone and parchment.[13]
So, during 1278 King Edward I of England provide swords made of whale bone and parchment for tournament weapons, which makes me curious: what did the sword look like (I mean physical image either painting or real artifact or replica)?
So far I found some discussion about the property of the whale bone (baleen) sword but from the explanation it is hard for me to see or imagine what it looked like so I'd appreciate it if someone could provide an image or shape of the whale bone (baleen) sword and how it was made. http://myarmoury.com/talk/viewtopic.php?t=10426
Aparently the whalebone sword or baleen is covered with parchment; it is not a separate sword, based on this link provide by @JustCal so I have deleted the question regarding parchment sword.
