Perforation Uses | Ties
Per Inch | Types | Internal Folding
Perforations on continuous forms can be used on
the left and right sides of the form to make a stub so that the lineholes can
be easily removed after the form has been through a printer. Perforations are
used as a means of keeping forms together in a continuous stream as they are
fanfolded, but allow the forms to be detached from each other after they have
been imprinted upon. Also, they provide a way to remove internal sections of
the form itself.
Ties Per Inch (TPI)
The tie or tab is the part of the perforation
where the paper does not get cut, but remains intact to "tie" the
paper together. The ties alternate with cut areas to form the perforation. The
tied areas of the perforation are usually narrower than the cut areas to allow
for easier detachment of the sections separated by the perforation. The proper
TPI to use is generally determined by the type of form and the function of the
perforation on that form. The following are some of the common TPI and their
uses on continuous forms:
- 4 TPI: 4 TPI is the most often used stub perforation for single and
multi-part forms. It allows for easy removal of the stub and lineholes once
the form has been run through the printer. 4 tie is also used as a folding
perf, but should be used with caution because it tends to break easily, especially
on multi-part sets. It should not be used on letterheads when a cleaner edge
is desired after the perfs are detached.
- 6 TPI: 6 TPI is also used as a stub perf, but it does not detached
as easily as a 4 TPI. It is sometimes used for the stubs on the first and
last parts of a multi-part set of 5 or more parts. It provides more strength
to the entire set so that the stubs will not loosen up before the form has
been through a printer. It also is the most popular TPI for fanfolding both
on single and multi-part forms. It provides strength to hold the continuous
stream of forms together so that they will not fall apart when going through
- 8 and 10 TPI: The perforations in this group can be used as stub
and internal perforations, but are most often used as folding perfs on one
part forms of a heavier stock, such as 32 lb. ledger and 100 lb. tag. They
are also used on multi-part sets to provide more strength with the fanfolded
- 12 TPI: 12 TPI is also referred to as a "statement perf".
It is most often used as a perf within the form that allows the user to remove
a section of the form. For example, the top or bottom section of a "statement
of account" form may be removed to be sent back with a payment. A 12
TPI perforation is durable and many times it is best to fold over the perf
so that it detaches easier. It can also be used as a folding perf on heavier
- Letteredge or Invisible Perf: As the name implies, the letteredge
perf is nearly invisible and leaves a clean, smooth edge after the perf is
detached. It is most often used for all of the perforations on letterhead
forms because of the clean look it leaves when detached. The most common ties
per inch for letterhead perfs are 50, 66, and 72. Most forms manufacturers
use one of these as the standard for all of their letteredge perfs unless
a specific TPI is requested. Letteredge or invisible perfs should not be used
for fanfolding on multi-part sets or on single part forms that are of a paper
stock heavier than 28 lb. ledger. It is too difficult to control the cutting
depth of the perf which may result in a perforation that does not detach properly.
- Horizontal perforations run left to right across the form.
- They have limitations on the number and position of perforations
- Partial perforations do not run across the full width of the form.
9 1/2" x 11"
9 1/2" x 11"
- Vertical perforations run down the depth of the form.
- The number and position of the perforations is usually not critical
for full vertical perforations.
- Partial vertical perforations do not run the entire depth of the
- The number and position of partial perforations are limited. Consult
your supplier for these limitations.
9 1/2" X 11"
9 1/2" X 11"
Internal Folding Perforations
In addition to folding perforations used for fanfolding, continuous
forms may also have internal folding perforations. The internal perfs are not
actually folded, but are necessary when the finished form is smaller than the
depth at which the press or collator can actually do the fanfolding. Most presses
are set up to print forms only at preset depths. On a 22" press for example,
the 22" represents the circumference of the printing cylinder and only
the form depths that can be divided into 22" can be printed on that press.
11", 7 1/3", 5 1/2", and 3 2/3" are the common preset depths
of forms that the 22" press can produce. When fanfolding on a 22"
press or collator, the common fanfolding depths are 11" and 7 1/3".
A 5 1/2" form would not be folded at 5 1/2", but at 11", so each
11" sheet would contain two 5 1/2" forms. The perforation separating
the two 5 1/2" forms on the 11" sheet would be known as the internal
folding perf. Since folding weakens perforations, the folding perf needs to
be of more ties per inch than the internal folding perf so that both perforations
will burst or detach using equal force on both. For example, you may find that
on a single part form of 20# bond, an 8 tie perf will be used for the folding
perforation and a 6 tie will be used for the internal folding perforation. The
8 tie is a stronger perf than the 6 tie, but it will weaken slightly when folded
so that it will be comparable to the 6 tie unfolded perf.
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