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Dot Gain and Tone Value Increase in Print
Learn how dot gain and tone value increase are measured, how to read TVI curves, and how to agree print targets and compensation with your packaging converter.
Tone value increase (TVI), often called dot gain, is the difference between the tone value in your file and the tone value measured on the printed sheet. A hypothetical nominal 40 percent patch that measures 57 percent has 17 percentage points of TVI. That figure is an optical and mechanical measurement, not a direct measure of physical dot area or ink volume. Targets depend on print process, substrate, instrument, reference patches and agreed print condition, so confirm them with your converter before changing files.
What dot gain and tone value increase measure
Tone value describes a printed screen tint on a percentage scale between the substrate and solid ink. In densitometric measurement, apparent dot area is calculated from tint, solid and substrate density readings; it is not simply the tint density divided by the solid density. Tone value increase (TVI), often called dot gain, is the difference between the printed tone value and the tone value in the original file. In a hypothetical example, if a control patch for a 50 percent tint measures 68 percent, the TVI is 18 percentage points. That is not an 18 percent relative increase. To get relative increase, divide the TVI by the nominal tint and multiply by 100, which gives 36 percent here. The distinction matters when comparing reports or setting tolerances.
TVI is a measurement of printed screen tints, not a direct measurement of physical dot area or ink volume. A densitometer calculates apparent dot area from density readings of a tint, a solid and the substrate. The Murray-Davies equation is one common calculation. The Yule-Nielsen version adds an empirically determined factor to estimate physical dot area for specific inks, paper and process. Measured dot gain includes mechanical gain from growth of the physical halftone dot and optical gain from how the dot appears due to light refraction in the substrate.
- Tone value is expressed on a percentage scale referenced to the substrate and solid ink, not as a simple percentage of solid ink density.
- TVI compares printed tone value with the file value.
- A normal reflection densitometer reading includes mechanical and optical effects.
- A microscope or magnifier can be used to assess mechanical gain separately.
Why the same file can print darker or lighter
Press and material changes move tone value. X-Rite notes that solid ink density can change with ink film thickness or volume, while dot gain can change with impression pressure or blanket and packing condition. Substrate, halftone screening, ink and measurement conditions also affect the result. This is why a file that looked correct on one job can print heavier on another.
TVI is not one number for every tint. It is a curve. A hypothetical set of measurements might show 9 points at a nominal 18 percent patch, 17 points at 40 percent, and 14 points at 70 percent. Midtones often show the largest change, but the actual peak depends on the measured curve, process and materials. Do not assume that a correction measured at one tint applies unchanged at another.
Color balance can shift when channels gain unevenly. If cyan, magenta and yellow do not increase by the same amount at the same tint, gray balance and critical overprint colors can move. Equal gain across channels is not a guarantee of neutral appearance, because ink, substrate and color management also matter. Treat channel balance as something to measure, not something to assume.
A hypothetical worked example
Suppose a converter prints a control strip with nominal tints of 18, 40 and 70 percent. The agreed method is a reflection densitometer using the converter's reference patches and print condition. The hypothetical readings are 27, 57 and 84 percent. The TVI values are 9, 17 and 14 percentage points. The relative increases are 50 percent for the 18 percent patch, 42.5 percent for the 40 percent patch, and 20 percent for the 70 percent patch. None of these figures tells you the physical ink area or the ink volume transferred.
Now suppose the designer wants a printed 40 percent cyan tint. A naive correction would subtract 17 points from 40 and ask for a 23 percent file value. That is only a first trial, not a validated correction. Gain at 23 percent is not guaranteed to be 17 points, because the curve changes with tint level. The same caution applies to the 18 percent target. Subtracting 9 points gives 9 percent, but the gain at 9 percent may differ. The next step is to print a new trial with the converter's agreed compensation method, measure the same patches, and compare the new curve with the target.
| Nominal tint | Hypothetical measured tone value | TVI in percentage points | Relative increase |
|---|---|---|---|
| 18 percent | 27 percent | 9 | 50 percent |
| 40 percent | 57 percent | 17 | 42.5 percent |
| 70 percent | 84 percent | 14 | 20 percent |
Instrument, patch and print condition
TVI numbers are only comparable when the measurement method is comparable. Ask which instrument was used, whether it was a densitometer or spectrophotometer, which reference patches were measured, what illumination and backing were used, and which print condition the target represents. The published X-Rite table of typical values for sheet-fed offset, web offset and non-heatset web is an illustration of how values differ by printing condition. It was measured with Status-T and the Murray-Davies equation at a 50 percent film tint. It is not a current packaging target and should not be copied into a specification without the converter's agreement.
Agree a measurement method for spot color tints. SCTV, described in ISO 20654:2017, uses spectral reflectance to produce tone values between paper at 0 percent and solid ink at 100 percent. For a hypothetical linear SCTV reproduction target, a nominal 50 percent patch would target 50 percent SCTV, a zero percentage-point difference. This is a target, not a result guaranteed by the calculation; the printed patch must be measured. A traditional density-only instrument cannot provide SCTV. Do not apply a CMYK TVI target to a spot color tint without confirming the method with your printer.
Agree targets and compensation ownership
There is no universal TVI target. A target belongs to a print condition: process, substrate, ink set, screening, instrument and measurement procedure. Ask your converter for the target curve, the acceptable tolerance, the control patches and the measurement report format. If the converter provides an ICC profile, ask which calibrated print condition it characterizes and how files should be prepared for it. A profile and press calibration can be complementary parts of the same workflow. An additional file adjustment that duplicates compensation already handled elsewhere can make the result lighter than intended.
Decide who owns compensation. In one workflow, the converter's calibration brings the press to an agreed condition and the designer supplies files for that condition. In another, the designer applies a compensation curve to the files. Both can work, but mixing them without documentation creates confusion. Record the decision in the job specification, along with the target print condition and the proofing method.
Decision table for common TVI situations
Use this table to frame the conversation, not to replace the converter's measurement data.
| Situation | What to confirm | Practical action |
|---|---|---|
| New packaging artwork | Target print condition, substrate, ink set, TVI curve and tolerance from the converter | Design and proof to that condition. Do not use a legacy table as the target. |
| Artwork moving to a new substrate or process | Whether the existing TVI curve still applies | Request a new measurement or profile. Plan a trial and compare control patches before approving color. |
| Proof looks lighter than the printed sheet | Whether proof and print use the same reference patches, instrument and compensation | Ask for measured values from both. Do not adjust files from visual memory alone. |
| Spot color tint | Agreed spot tint method, such as SCTV, and reference patches | Measure with the agreed instrument. Do not assume CMYK TVI applies. |
| Digital print job | The digital press calibration and color profile | Confirm whether the file or the press controller handles compensation. Avoid adding a second curve. |
| Tight brand color or gray balance | Channel by channel TVI and overprint behavior | Review measured curves with the converter. Set tolerances and approval criteria. |
Practical checklist
Use this checklist as Teal's editorial planning framework for a review conversation with your converter.
- Ask for the target print condition, substrate, ink set and screening before you set a TVI target.
- Request the measured TVI curve at several tints, not a single number.
- Confirm the instrument, reference patches, illumination, backing and sample preparation.
- Record nominal and measured tone values separately, and label TVI as percentage points.
- Confirm which calibrated print condition the ICC profile characterizes and whether any proposed file adjustment would duplicate compensation elsewhere in the workflow.
- Print a trial with the agreed compensation method and measure the same patches again.
- Compare cyan, magenta, yellow and black curves for balance, but do not assume equal gain gives neutral color.
- Use SCTV or another agreed method for spot color tints.
- Keep the approved curve, proof and measurement report with the job specification.
- Escalate to the converter if the measured curve falls outside the agreed tolerance.
Scope limits
This guide is an editorial planning framework for discussing TVI with a converter. It is not a press adjustment procedure, a color management certification or a compliance determination. It does not tell you how to set impression pressure, blanket packing, ink film thickness or plate curves on a press. Those are converter responsibilities and should follow the converter's instructions and safety procedures.
It also does not establish a universal target, a universal file compensation curve or a guarantee that a given file will match a given substrate. The hypothetical numbers are arithmetic examples, not a quote, market benchmark or validated production result. Confirm channel requirements, customer color tolerances and any contractual obligations in your own agreements.
Questions about Tone value increase measurement and file planning
Is dot gain the same as tone value increase?
In common print discussion, yes, TVI is often called dot gain. Technically, measured dot gain includes mechanical and optical effects, and it is calculated from density readings of a tint, a solid and the substrate. It is not a direct measurement of physical dot area or ink volume. Use the term TVI when you need to be precise about the difference between file tone value and printed tone value.
Can I correct TVI by subtracting the measured gain from my file values?
Not reliably. Gain changes with tint level, so a correction measured at 40 percent does not apply unchanged at 23 percent. A subtraction may give you a first trial value, but you need a new printed test and measurement to validate it. Work with your converter's calibration and ICC workflow, and decide who owns compensation so you do not apply two corrections.
What TVI target should I use for packaging?
There is no single target. The target depends on the print process, substrate, ink set, screening, instrument and agreed print condition. Ask your converter for the target curve and tolerance for your job. Published tables for sheet-fed, web offset or newspaper printing illustrate how values differ by condition. They are not current packaging specifications. For spot color tints, ask whether SCTV or another agreed method applies.
Sources and further reading
- Measuring Density with A Densitometer? | X-Rite Blog: Defines tone value as dot area, defines TVI as the difference between printed tone value and file tone value, gives the 50 percent to 68 percent example, and states that SCTV uses linear target values under ISO 20654:2017.
- Understanding Graphic Arts Densitometry: Explains that measured dot gain includes mechanical and optical gain, describes the Murray-Davies and Yule-Nielsen calculations, and lists published typical dot gain values by printing condition measured with Status-T at a 50 percent film tint.