Sand-particle-size distributions (PSDs) are used for various purposes in sand control: for example, decision making between various sand-control techniques and sizing of the filter media (sand screens and/or gravel packs) through either rule of thumb or physical experiments or theoretical models. PSDs of formation-sand samples are also often used to generate “simulated” formation sand for laboratory experiments. The two most commonly used techniques for PSD measurements are sieve and laser. Although some engineers use one technique for no obvious or justifiable reasons, others use both techniques for measurements and do not know what to do with the data when significant differences exist in PSDs obtained from each technique. Although the inherent limitations of (and the differences between), these two techniques as well as other factors affecting the measurements are well-known, a systematic study as to which of these two techniques is relevant to sand-control-screen selection and why is lacking. In this study, we critically review the current practices in PSD determination and the use (and misuse) of the information obtained from these measurements, propose a methodology toward determining what is relevant under gradual-formation-failure conditions for wire-wrap screen, discuss when it should be used and why, and present initial experimental results that support our conclusions.