In order to engrave the sword, Casandra softens the steel by annealing it. First, she puts the blade back into the forge and heats it to the point at which is austenizes. The carbon and steel molecules begin to mix, just like when it is normalized. However, the blade is allowed to slowly cool down, making it soft.
Once the blade is soft and cool, Casandra takes out specialized tools and carefully etches the figure of King Eric into the blade. Tall, dark, and handsome, his figure can be seen when the blade is held up properly to the light. Casandra follows the grain of the blade and the patterns that she has worked into the blade--by folding it over and over. As she etches, she slowly infuses the blade with the power of trump.
When she is finished etching, Casandra uses coarse stones to polish the blade and create the edge. She uses successive grades to polish the blade. However, the steel is still too soft to maintain this edge. So, Casandra heat treats the blade to harden it. The steel is once again heated to the austenization point. However, because the blade must be heated evenly, Casandra heats it in a salt bath instead of in the forge. Although the salts melt at a point below the austenization point of the steel, they remain in a liquid state past the austenization point.
Once the steel is uniformly heated, Casandra removes the blade from the salt bath and plunges it quickly into the quench tank, which is filled with oil. The oil allows the steel to cool quickly and evenly. This, in turn, traps cementite in the iron, and creates martensite, a very hard steel that holds an edge well. Casandra repeats this process two more times until she is satisfied with the blade.
With the blade sufficiently hardened, Casandra tempers the edge. Tempering allows the blade to maintain its sharpness. As is customary with Japanese swords, only the cutting edge is tempered. The blade is heated once again, but this time it is not heated to the austenization point. In addition, Casandra coats the blade, except for the edge, with a mixture of wet clay. The clay dries out and hardens as the blade is heated and retains the heat and slows the cooling process. This results in the edge being very hard, while the back of the katana is soft and retains its flexibility.
The final step in creating the blade is an acid wash. Casandra bathes the blade in an acidic solution that removes some leftover impurities and brings out the contrast between the different layers in the sword. This results in a swirling pattern that reminds one of the Great Pattern of Amber. In addition, the designs in the steel compliment the careful etching that Casandra used in creating the portrait of her father. Although Eric's visage is difficult to see, it shows up distinctly when the blade is seen from the proper angle.
Casandra now works on converting her blade into a weapon. First, she constructs the scabbard, or saya. Casandra has already selected a long piece of wood from a very old ho tree. She uses the blade as a template to create the sheath. Next, she creates the small metal habaki, which fits on the blade next to the tang and prevents the blade from moving inside the saya.
Casandra adds the handguard, or tsuba, which is made of shining steel and forms the shape of a Chinese dragon. Next, Casandra attaches the tsuka (handle), and covers it with menuki, or hilt ornaments. The menuki is made of black pearls, strung together with hairs from Hoshi's tail. Finally, Casandra screws the pommel into place. Genkun [my honored father] is complete.
Casandra places a finger 5 cm (2") from the hilt and notes that the blade balances perfectly. Next, she hold Genkum blade up and drops a 25 cm (10") square of silk. The blade cleaves the silk neatly as soon as the silk touches the blade. Casandra bends the blade to each side to verify its flexibility. Finally, she sheathes and unsheaths the blade silently. It is done.
Casandra's new blade is extraordinarily beautiful. In fact, it is more a work of art than a blade. The benefits of the techniques and materials Casandra used are in the beauty of the final product. However, that beauty is at the price of durability. While the edge will remain sharp, ordinarily the blade itself would be too brittle to stand more than light blows. It is only the trump image within the blade that will keep it from breaking.