After Christ was scouraged, one of the Roman soldiers platted a crown from a nearby thorn bush, placed it on His head and gave him a reed as a scepter.
This full sized reproduction of what the crown may have looked like was based on the evidence found on the Shroud of Turin. According to analysis of the shroud, the crown was probably more like this cap than a platted wreath as traditional shown in artwork.
The Eastern Orthodox Christians often display miniature replicas of the crown (usually made of silver) during the lenten season. This replica is a good display of the Passion of Our Lord during this time leading to Easter, and makes for great meditation.
This more traditional design, the wreath-style crown, is the same as seen in Mel Gibson's The Passion of the Christ. It is made from the same thorns as the crown above, but has been artificially darkened using several layers of paint to match the screen prop.