Now you can bring back the deep black color and luster your black hard rubber pens and pencils once enjoyed by using Pennsbury Manor Black Hard Rubber Pen Potion No. 9 to re-blacken the oxidized, faded, and browned-out color that time and exposure to the elements has caused.  Unlike other methods, like Enzymatic, or Microbial, heavy sanding and buffing, or other chemical process (Chlorine Bleach), Pen Potion No.9 removes no surface material.  It leave the surface details just as it was before treatment.   It uses the very coloring agent that was used when the pen was originally made. Pennsbury Manor Black Hard Rubber Pen Potion No. 9 is a dye that imbeds with the rubber and bonds with the original rubber in a most satisfactory way.  It is a water-based, black liquid dye that bonds with rubber but will not bond with the metal parts of the pen, so clean up of any overcoated metal is a snap. When cured, Pen Potion No. 9 leaves a protective UV resistent shell that will resist sun. and water damage for decades.    The resulting restored color can be hand-buffed to a sheen as you can see in the pictures above.  For an even higher gloss, use Pennsbury Manor SuperShine Pen Potion No.10.   PMHBRPPNo9 comes in 1 and 2 oz bottles – enough to restore from 15 to 40 pens or more.
 
There are a few products on the market that promise to "de-oxidize" hard rubber and bring black hard rubber back to black.  Caution:  Another word for "deoxidize" is "remove". Whether by chlorine chemicals, microbial or enzymatic methods, rubber is removed to get to the underlying yet un-oxidized rubber.  One reason, many pen restorers have shied away from removing surface rubber is because of the loss of the detail in the faint etched patterns or lettering on the pen.  The second reason is that the newly exposd rubber surface will oxidize again unless protected.