First off, as we speak, these are highlighters that have been bought back in August during the '07-'08 Back-to-School season and with that being the case, in this current point and time, there's still some "gas left in the tank", so to speak. In other words - from daily usage ever since I bought these, only two of them have ran out on me concerning the ink, and that undoubtedly says a lot since you can rest assure that these highlighters are indeed the "real deal" and could be even comparable to considerably the more-well known highlighters from Sharpie - those being the Accent type.
Upon comparing a yellow one from that of Staples and another from that of Sharpie, I found very, and I mean very little difference between them two as far as "quality" goes. The Sharpie had a darker output, whilst the Staples one had one that it would take you a magnifying glass to be able to notice the extremely little difference in terms of the quality. I had bought these online (the regular chisel tip) when they were available during the time (although I'm pretty sure they were always in stock - may be wrong though) which came in a dozen, with four different colors, those being yellow, pink, blue and green. Three of each is what you'd find, all ensuring a good output regardless or in some cases, depending upon what you use them on. In the end, I was very much satisfied since highlighters, for the most part, usually run for a dollar each. With the fact that each highlighter contains an high ink supply in tact along with desired quality, you just can't go wrong with these!