Every weapon/cloth/accessory has a degree

Weapons

Every weapon/cloth/accessory has a degree. In every degree, there are 3 specific levels of this item. The first (lowest) level of each degree is called main level. NPCs sell only main level items and also all the SOx items are always main level items.

You can use alchemy to change the stats of a weapon, add new attributes on it or make it +1 or higher.

To change the stats of a weapon or add new attributes on it, you have to create the related stones and fuse them on the weapon. If the fusing is successful, the new stats will appear.

If you want to make a weapon +1 or higher, you have to fuse weapon elixirs on the weapon. If the fusing is successful then the + number will be raised by 1, otherwise you will lose the + it had.

The +3 (or higher) weapons look different when you hold them. They have an inner glow and the color of this glow depends on the + number:
+3 +4: White
+5 +6: Pink
+7 +8: Gold
+9: Cyan
Degrees 1 2 3 4 5 6 7 8
Levels 1
3 5 8
10 13 16
18 21 24
26 29 32
35 38 42
45 48 52
56 60 64
68 72
Chinese weapons
Blade
Bow
Glavie
Spear
Sword
Shield
European weapons
Cleric rod
Crossbow
Dagger
Dual axe
Harp
One-handed sword
Staff
Two-handed sword
Warlock rod
Shield
http://www.silkroad-online.gr/index.php?display=weapons&lang=en