Pentel Hi-Polymer Eraser review and comparison tests

Ever since I took a technical drawing class in college, the Staedtler Mars Plastic was my eraser of choice for its erasing effectiveness and non-abrasive nature that prevented damage to most papers. As my exposure to Japanese stationery items grew (thanks largely to Jet Pens), my favorites became the Pilot Foam and the Mitsubishi Uni-ball Boxy erasers for their self-cleaning nature (their erasure debris tends to clump together into a single strand for easier removal from the drawing surface).
Oddly despite the rather large proportion of Pentel mechanical pencils in my collection, I never got around trying one of their block erasers until this week. Thus enjoy my unscientific comparison tests cobbled together with some of the drawing supplies from my collection and the sample erasers generously provided by Kristen and Nicole from Pentel's PR an Marketing Communications departments.
On this regular graphite lines test on white card stock, both the Pilot Foam ER-F10 and the Pentel Hi-Polymer ZEH10 erased them cleanly without leaving any traces nor damaging the paper. Either one would be a good choice for a field sketching kit. While in general I do not tend to use erasers too often while drawing with the softest darkest grades of the graphite range, I thought it would be fun to do a few eraser comparison tests with a variety of pencil brands and support papers to put the block erasers through more challenging trials.
Erasers' comparison chart (Mitsubishi Boxy EP60-BX, Pentel Hi-Polymer ZEH-05, Pilot Foam ER-F10, and Pentel Hi-Polymer ZEH10) on Georgia Pacific white card stock using swatches drawn with Tombow Mono (3H to 6B) wooden pencils.
Erasers' comparison chart (Mitsubishi Boxy EP60-BX, Pentel Hi-Polymer ZEH-05, Pilot Foam ER-F10, Pentel Hi-Polymer ZEH10, and Staedtler Mars plastic) on 150 Canson Fanboy Drawing paper using swatches drawn with Faber Castell 9000 (2H to 8B) and Mitsubishi Uni-ball Penmanship Writing (4B & 6B) wooden pencils.
In this Staedtler Mars Ergosoft pencils (HB, B, & 2B) test index card, the Pilot Foam eraser erased the graphite swatches faster but producing considerably more erasure debris while the Pentel Hi-Polymer eraser accomplished the same task on the HB and B swatches with considerable less wear. Thus the Pilot Foam eraser would be a good choice for users that prize speed regardless of how quickly it gets used up, and the Pentel Hi-Polymer eraser would suit users that value a longer lasting eraser with similar erasing performance that takes just a bit longer and a tad more elbow grease to get the job done. My old Staedtler Mars Plastic eraser acquitted itself well with the HB swatch, but left a darker ghost residue after erasing the 2B swatch. Given its bulkier size, it hasn't seen much use lately since I favor more compact erasers in my field kits.
For the final comparison test, graphite swatches were applied heavily to this gridded index card with a selection of Mitusibishi Hi-Uni wooden pencils ranging from HB through 10B grades. The Mitusibishi graphite's waxier formulations tend to be harder to remove completely, but all three erasers did a fair job with the HB swatch.
After erasing the graphite swatches from 2B to the softest 10B, all three erasers left visible graphite ghost residue on the index card. There was no significant difference in performance among the these block erasers at the harder middle-of-the-range graphite grades most often used for writing and preliminary sketching. Ultimately retail price and local availability would likely be the determining factors in selecting one of them, but any of the erasers tested are likely to meet the needs of the average student and artist under normal field conditions. Thus the Taiwanese Pentel Hi-Polymer erasers held their own against my favorite German and Japanese block erasers.