Series 2004 $20 note
When the notes of Series 1996 were introduced, the Treasury indicated that these new designs would not be so long-lived as their predecessors. Instead, redesigns would occur much more frequently, keeping U.S. currency always ahead of the advances of those seeking to counterfeit it.
In keeping with this policy, a new $20 note design was released to circulation late in 2003. The new notes, dated Series 2004, are the first small-size notes to be printed with background color; they have peach, green, and blue tints. These notes also retain, and improve upon, the security features introduced with the 1990 and 1996 series. Microprinting is present in both the engraved black face design (along the bottom border just below the Treasurer's signature) and the blue face underprint (along the edges of some of the letters in "USA TWENTY"). The color-shifting ink shows a greater color change than did that used on the Series 1996 notes, changing from green to a bright copper color instead of from green to black. In addition, a new metallic ink has been used for the small eagle and shield just to the right of the portrait, and a yellow ink which is difficult to photocopy has been used for many small numerals "20" on the back of the note.
The second redesigned note in this series, the $50, was issued in late 2004. The $50 has tints of peach, purple, blue, and red in the background; this different color scheme makes the $50 visually distinct from the $20 despite their general similarity of design. The $50 also has a large untinted space on the back for the vignette of the Capitol building, allowing the traditional green back printing to appear more clearly. Additionally, the $50 retains all the security features of the $20. Microprinting is present in two of the stars in the left background, as well as in its former locations in Grant's collar and in the side borders of the face design. The color-shifting ink on the face, and the yellow ink used for the many small numerals "50" on the back, are the same as on the $20; but the blue star just right of center on the $50 uses a different metallic ink from the green eagle on the $20. Finally, the watermark of Grant remains in the paper at far right, and the polymer strip embedded in the paper has been widened slightly, to make the flag design and "USA 50" on it larger and easier to see when the note is held to the light.
The colorised $10 note was released in early 2006. This note has background tints of peach, orange, and red. Like the $50, the $10 has an untinted space on the back around the vignette. However, the $10 also has additional untinted areas on both sides around the watermark, and has a single-color back tint instead of the three-striped pattern appearing on the $20 and $50. Microprinting appears in both side borders of the face design, along the ribbon carrying Hamilton's name, and along the lower edge of the red torch at left. Small yellow numerals "10" appear on the face side of the note as well as the back. The color-shifting ink is like that on the colorised $20 and $50, while the red metallic ink used for the torch to the right of the portrait is new. The paper retains a watermark of Hamilton, and also a polymer security thread of the same width as that in the previous $10 design, not of the increased width used in the 2004 $50.
The next denomination to be colorised was the $5, released in early 2008. Its background is tinted pink, gray, and purple; it follows the $10 in having untinted areas surrounding both the main watermark and the back vignette, but it follows the higher denominations in having a three-striped tint on both sides. The watermark at right has been changed from Lincoln to a large "5", and three more numerals "5" appear as watermarks just left of the portrait. The polymer security thread has been repositioned between the portrait and the Treasury seal, and the printing "USA 5" on it is now in a completely different style than used on other denominations. Small yellow numerals "05" appear on both sides of the note, and microprinting appears in both side borders of the face design, in the purple shield on the face, and also in the large purple "5" on the back--the first use of microprinting on the back side of a note. The $5 lacks both the color-shifting ink and the metallic ink used on the higher denominations.
A redesigned $100 is scheduled to follow in 2009. Few details of its design have yet been announced, though the BEP has revealed that it will carry at least one new, more advanced security feature: an embedded strip bearing holographic images that appear to move as the note is tilted. This colorised $100 will complete the current design generation; as in the previous cycle of new designs, no changes will be made to the $1 or $2 notes.
The BEP has also recently begun another upgrade of its printing equipment, this time adopting new presses capable of handling larger 50-subject sheets as well as the current 32-subject sheets. These new presses are being phased in over a period of perhaps five years, but during this transition period all currency will continue to be produced in sheets of 32 subjects; only after the new equipment is in place will the BEP switch over to the larger standard sheets. The new presses will also make it possible for additional advanced security features to be added to the next generation of currency designs, likely to go to press around 2013--already the BEP is conducting testing of potential new security features and printing techniques.