Traditionally, sabers are characterized by their curved blades. The curved design of the saber blade helps facilitate effective cutting and slashing motions, while the curve also assists in drawing the blade from the scabbard smoothly. The curve of the blade allows for better distribution of force along the cutting edge.

However, it's worth noting that variations and adaptations of sabers exist, and some may have straight blades. These straight-bladed sabers are often referred to as "straight sabers" or "backswords." They feature a single-edged, straight blade with a single cutting edge and a sharpened tip.

Straight-bladed sabers were used by various cultures and historical periods. For example, the European backsword, a type of straight-bladed saber, was prevalent during the Renaissance and early modern periods. They were typically single-handed weapons used by cavalry and infantry.

While straight-bladed sabers are less common than curved-bladed sabers, they can still be effective weapons for cutting and thrusting techniques. The straight design allows for precise thrusts and direct cuts.

If you have a particular interest in a straight-bladed saber or any specific historical weapon, it is advisable to consult reputable sources or seek guidance from qualified instructors or historians who can provide accurate information and guidance on the specific characteristics and usage of those weapons.