Testex™ Press-O-Film™ Replica Tape

Testex Press-O-Film replica tape consists of a layer of crushable plastic microfoam coated onto polyester film of highly uniform thickness. It is sold in a number of grades to accommodate measurements in different profile ranges.

Testex Press-O-Film HT is an improved version of Press-O-Film (discontinued in 2010). Press-O-Film HT (High Temperature) is formulated for better performance at high temperatures (up to 140°F or 60° C) encountered in the most challenging environments.

Replica tape consists of a layer of compressible foam affixed to an incompressible polyester substrate. When pressed or “burnished” against a roughened (steel) surface, the foam collapses and creates an impression of the surface. Placing the burnished tape between the anvils of a micrometric thickness gage, and subtracting the contribution of the incompressible substrate (50 µm or 2 mils), gives a measure of the average maximum peak-to-valley height of the surface profile.

In 2024, a comprehensive study was performed to determine an accuracy statement for replica tape. That study determined the following accuracy and precision statements:

The study, and the above accuracy statements, were determined under the following conditions:

The procedure detailed in the instructions is followed

• The High Accuracy Burnishing Tool is used
• All readings are converted using a Testex Digital Micrometer, PosiTector RTR H, or conversion table
• At least two readings were taken per measurement and averaged, in accordance with the written procedure found in the Number of
• Readings section of the instruction manual

Industrial steel in bridges, ships, railcars, etc., is almost always painted or otherwise coated to prevent corrosion. Before they can be painted, these metal surfaces must be cleaned and roughened to ensure that the paint adheres. This is usually done by blasting the surface with abrasive. The height of the surface profile has been shown to have a significant impact on coating adhesion and resistance to corrosion.

Most international standards instruct users of replica tape to take two replica tape readings in each measurement area, and average those two readings together to yield a ‘Profile Measurement’. As with any test, averaging multiple measurements improves repeatability and accuracy.

If a measurement made with either Coarse or X-Coarse replica tape is in the ‘overlap range’ of 38 to 64 µm (1.5 to 2.5 mils), a second measurement should be taken in the same spot with the other grade of tape. If BOTH readings are in the above Overlap Range, record the average of the two measurements as the peak-to-valley roughness. If EITHER reading is outside of the Overlap Range, record it as the profile height.

For more information, consult the Testex Press-O-Film Replica Tape Instruction manual.

In 2024, a peer-reviewed study introduced improvements to the replica tape test method including an increased range for Coarse, X-Coarse, and X-Coarse Plus replica tapes and a new conversion technique. The resultant conversion table can be used with analog micrometers and provides a simpler alternative to the legacy ‘averaging’ technique. The conversion table is not required for the Testex Digital Micrometer as it makes the calculations automatically.

Previously, if readings made with either the legacy Coarse or X-Coarse replica tape fell within the ‘overlap range’ of 38 to 64 µm (1.5 to 2.5 mils), a second reading was be taken in the same spot with the other grade of tape. If BOTH readings were within the above ‘overlap range’, the average of the two readings were recorded as the ‘Profile Measurement’. If only one reading was outside of the Overlap Range, it was recorded as the first reading and a second reading was taken with the same grade of replica tape. Averaging those two readings together yielded a ‘Profile Measurement’. The legacy averaging technique is still valid and supported by international standards.

For more information, consult the Testex Press-O-Film Replica Tape Instruction Manual.

The High Accuracy Burnishing Tool includes a spring-loaded burnishing ball which is depressed into the base of the tool exerting the perfect amount of pressure to burnish (create) a replica. It reduces operator influence, providing an extended range and ±8 µm (0.3 mil) accuracy for Testex Replica Tape.

For concave surfaces, the narrower curved top of the tool can be used to create replicas.

The Classic Stick-type Burnishing Tool remains a valid measurement practice and is recognized by international standards. Care should be given to avoid applying too much force. Excessive force can lead to inaccurate measurements.

All versions of Coarse and X-Coarse replica tape use the same trusted replica foam, incompressible backing, and HT (high temperature) formulation that have been sold for decades. There is no functional difference between the legacy rolls of Coarse and X-Coarse replica tape, and the new strips of Coarse and X-Coarse replica tape that are packaged in cartons.

The new ‘strips’ of Coarse and X-Coarse replica tape simply feature a modernized design and packaging.

Strips of X-Coarse Plus replica tape feature thicker foam to allow an increased measurement range of 100-150 µm (4.0-6.0 mils). Strips and rolls of X-Coarse Plus replica tape should not be used interchangeably.

Improvements include:

• Easy-Open, Easy-Close Carton
• Improved ‘Strip’ format with Easy-Remove ‘Peel-Here’ Tab
• Increased X-Coarse Plus Range—100-150 µm (4.0-6.0 mils).
  
  

Returning Features

• Same trusted Coarse and X-Coarse replica foam
• Same High Temperature (HT) Formulation for better performance on hot surfaces
• 50 strips (impressions) per carton/roll