A copy set is a stack of sheets of paper, usually between two and six in number. The sheets are treated so that when a person writes on the top sheet, the same writing appears on all the sheets; the effect is also achieved when the copy set is run through an impact printer. The sets are called carbonless to distinguish them from the copy sets of decades ago which, due to limited technology, required carbon paper. Copy sets are used most widely for preprinted forms where a human fills in the blanks.
Within a typical carbonless copy set:
By "suitable cement" is meant not ordinary padding glue, which would cause all sheets to stick together, but rather a proprietary solvent. Manufacturers differ in their choices of chemicals for the resin and dye capsules, so one manufacturers' cement may not work with another's paper. Similarly, mixing different brands of paper within a set may not work, as one company's dye may not react with another company's resin.
The configurations of coatings are designated thus:
The paper stock chosen is usually a bond of basis weight between 15 and 25 pounds. Thinner paper gives clearer images and requires less pressure in handwriting; thicker stock jams less in the printing process.
Typical Configuration. Below is a cross-section diagram of an ordinary four-part carbonless set. The edge of each sheet of paper is shown in its traditional color (white for the original, with copies in canary, pink and gold). The heavy black line on the top of some sheets represents the resin coating, and the black dots on the bottom of some sheets stand for the dye capsules — but in reality the coatings are transparent. The front of the white sheet (in the diagram, the top surface) is the usual location for handwriting, although handwriting also works satisfactorily on the fronts of the other sheets.
1st Part CB | |
---|---|
2nd Part CFB | |
3rd Part CFB | |
4th Part CF |
Xerographic or offset printing is routinely performed on the front of all sheets. However, the ink if applied to the back of a sheet will interfere with the dye capsules.
Self-Containment. The dye capsules appearing on the back of the sheet can cause a ball-point pen to skip. Hence self-contained (SC) carbonless was introduced to allow a copy to be made from a plain-paper original. In the case of a bank check, there are no capsules on the back to make endorsement difficult.
1st Part Plain | |
---|---|
2nd Part SC |
If an SC sheet is crumpled, images will develop in the creases because the dye capsules have been broken and the necessary resin is nearby.
The SC coating is almost always applied to the front of a sheet, as there are few cases where it is useful on the back. However, there is nothing wrong with having both the self-contained coating on the front of the sheet and the dye capsules on the back, as in this three-part set:
1st Part Plain | |
---|---|
2nd Part SC-CB | |
3rd Part CF |
Packaging. The best-known standard quantity of paper is the ream, 500 sheets. Manufacturers aim to to wrap precollated copy sets by the ream, but approximations are sometimes necessary because the numbers 3 and 6 do not divide evenly into 500. Here are the usual quantities:
Parts per set | Sets per wrapper | Sheets per wrapper |
---|---|---|
2 | 250 | 500 |
3 | 167 | 501 |
4 | 125 | 500 |
5 | 100 | 500 |
6 | 84 | 504 |
Collation. Some printing machines invert the sheets as they are being handled; others do not. To accommodate different equipment, manufacturers offer two collation schemes for precollated sets. With the three-part version as an example, here are the two sequences of factory packaging:
Forward (or Straight) Collation | Reverse Collation | ||
---|---|---|---|
1st Part CB | 3rd Part CF | ||
2nd Part CFB | 2nd Part CFB | ||
3rd Part CF | 1st Part CB | ||
repeat | repeat | ||
It is crucial that the sets be forward collated at the time of gluing. Otherwise some sheets will not adhere, and those that do adhere will not form correct sets.
For two-part sets the forward and reverse collations happen to be identical.
Standard Colors. These date back a number of decades, well into the era of carbon paper:
Color of Each Part | |||||||
---|---|---|---|---|---|---|---|
First | Second | Third | Fourth | Fifth | Sixth | ||
Number of Parts in Set | 2 | White | Canary | ||||
3 | White | Canary | Pink | ||||
4 | White | Canary | Pink | Gold | |||
5 | White | Green | Canary | Pink | Gold | ||
6 | White | Blue | Green | Canary | Pink | Gold |
All six of these colors are sold uncollated in each of CF, CB and CFB for larger sets or custom color combinations. Also, CF index stock in 90- and 100-pound weights is available in white and manila colors to give the set a stiff backing. Safety CB paper is available for bank checks. Ledger carbonless is sold in the traditional accountants' colors of white, buff and greentint.
Factory-collated sets are also sold with all sheets white.
Carbon Copy Sets. Old-time carbon copy sets often used manifold paper, a thin bond paper ranging from 7 to 11 pounds, along with carbon paper of a similar weight. With two layers of paper (one plain, one carbon) for each copy, such light stocks were required to allow the force from a pen to pass through.