Hundreds of style and font types are available when considering a scripted tattoo. The tattoo can be a single word or even letter or several sentences. It all depends on the meaning of the tattoo and how much body space you are willing to dedicate to the cause.
There are various styles of calligraphy, but the overlying theme for all types is beautiful, flowing letters. They can be somewhat simple or extravagant. Most are done in black and gray, though you have the potion of color and shading. Most calligraphy tattoos have a lot of detail so they need to be larger and placed on a flat surface to show that detail.
Sailor script tattoos are pretty basic and easy to read. A partial shading in either black and gray or color can make the script even more vibrant. These letters can be large enough to span your entire upper back or small enough to fit on your knuckles, since there isn't much detail. They are old fashioned and a permanent staple in the tattoo world.
Graffiti script is a more modern style of lettering and can be basic or extravagant. The individual letters can flow together or be separated based on style. Graffiti block letters are typically solid black while the more flowing letters can be shaded or filled-in with color to make them more vibrant. The overall style of the lettering will dictate whether or not it need a large surface area to adequately show detail.
Personalized script tattoos can be created by yourself or your artist. Writing the script yourself can make it all the more personal and unique though its beauty will be dictated by your personal abilities as an artist. Having your tattoo artist design the script may ensure a more beautiful piece. The style and attention to detail will determine how much surface area is necessary.