a method of inducing tag lines in an mri image is provided which allows adjustment of tag line width and spacing . the method includes determining a desired tag line width and then selecting a parameter of a sinc modulating function , such as main lobe bandwidth , in accordance with the desired tag line width . the method also includes determining a desired tag line separation and selecting a parameter of an rf pulse train based upon the desired tag line separation . a gradient field is applied to the specimen being imaged . the rf pulse train is modulated in accordance with the sinc modulating function and the modulated rf pulse train is applied to the specimen being imaged prior to an image acquisition operation . in one embodiment of the invention , the gradient is activated between pulses of the rf pulse train and is deactivated during the rf pulses .