Do Evaporation Lines Disappear? Tips To Prevent The EVAP Lines

If you have pregnancy symptoms such as missed period, but the evaporation line keeps appearing, what have you done wrong, or do evaporation lines disappear? 

Don’t be disappointed, as you may be involved in some common mistakes when you have a check with a home pregnancy kit test.

Consider the information below to find out the answer to the questions above and prevention tips.

What Is An Evaporation Line?

do evaporation lines disappear


An evaporation line stays at a similar location to the positive line on a pregnancy test.

In other words, the EVAP line is a slight streak replacing the positive line to indicate the false negative test.

Normally, such a line is visible after six minutes. Meanwhile, the positive one requires two minutes to appear.

Besides, the line appearing after around 10 minutes is an EVAP line rather than a positive one.

Are EVAP lines common? Not only are these strokes usual, but they are also confusing and disheartening.


When you check the result not early enough or have incorrectly taken the test, the evaporation line will appear.

Meanwhile, are EVAP lines colored? In fact, these marks have no color or look faint gray.

In some cases, the manufacturers produce pink or blue dye tests, which leads to the pink or blue lines of EVAP. It means the result is harder to read.

Do Evaporation Lines Disappear?

The EVAP lines are designed to stay visible until 48 hours after appearing. Most home pregnancy test brands guarantee that the line will remain on the test forever.

Particularly, after several days, the marks will fade and get thinner a little. Moreover, once the EVAP lines discolor the test kit, users can not renew it.

And do they glow while inverted? Most with pink color, including the ones dyed pink, turn into green once they are inverted.

Otherwise, the EVAP marks, which normally look whitish or gray, will keep the dull color.

Moreover, despite the exponential increase in the levels of hCG during the early pregnancy, the lines on the test do not tend to turn darker the days after.

How To Prevent Evaporation Lines?

When the answer to the question “Will an EVAP line eventually disappear?” is No, many people are looking for tips for prevention as they have to retake the test when this line appears.

Consider this advice to avoid wasting money and time on negative tests:

Follow The Instructions Printed On Pregnancy Test Kit  

The first steps of using the chemical pregnancy kit tests are always similar. However, the time frame applied to each is diversified based on different manufacturers.

Particularly, some brands require only two minutes for the lines to appear, while the others recommend the users to wait for up to five minutes.

Make sure you have read the leaflet inside before starting the first step – peeing. Thus, users will reduce the chances of inaccurate outcomes; you can save time and money.

Set A Timer

As mentioned before, when you leave the strip for too long, you get faint lines or clear blue easy evaporation lines (because of the dye).

If you take the waste of time and money seriously, you can set a timer for the testing process.

Consider the instructions attached with the product, especially the time necessary for waiting and setting the alarm.

Pick A Trustworthy Brand

Different brands have distinct techniques and elements used in their kit test. Thus, you should head for the reliable manufacturers providing high-quality products.

Besides, the EVAP lines even come out when the test is too sensitive. Thus, do some research before purchasing, even if they are displayed in pharmacies.

Inspect their sensitivity and accuracy on the company’s official website.

Should you have more time, visit the forum of women’s discussion to get some recommended names.

How To Distinguish Positive Result Lines Vs. Evaporation Lines

Line Thickness

This comparison has been revealed in the previous part. The thickness of positive result lines and evaporation lines is different.

Furthermore, the positive results are also similar to the control line of the kit test.

Meanwhile, the EVAP marks do not have consistent thickness. It will also look streaky in some cases.


Due to the similarity in appearance between the control line and result line, the dye used in the kit test greatly influences their color.

For instance, if the control line is dyed red, the positive result stripe also gets a pink look. Even when it is faint, the color of the dye is still visible.

What about the evaporation dashes? They are faint or nearly colorless as a normal water spot. Of course, they will never disappear.

In some instances, the evaporation line may be hard to recognize if you do not have enough close look.

Furthermore, no dye is visible in it, which sets it apart from the positive result line.

Reaction Time      

According to the time needed for reaction, you can tell apart an EVAP result and a positive one. Users always spend from three to five minutes waiting for the positive result to appear.

On the other hand, receiving the evaporation line takes around twice the amount of time. The reason is that the fresh urine used for the kit test will dry after 10 minutes, resulting in the EVAP mark.


Do All Pregnancy Tests Have Evaporation Lines?

The answer is No. Although the EVAP is popular in home kit tests, its appearance is not a must.

Particularly, the electric ones just provide two types of outcomes: being pregnant or not pregnant.

The second reason for this optional element is that some brands find distinguishing the faint positive and the EVAP ones hard.

For instance, the Clearblue EVAP lines in pregnancy tests have a gray color with a little blue shade from the dye. As a result, users would misread them as the faint positive ones.

How Many Types Of Pregnancy Test Lines?

After getting the answer to the question “How long do evaporation lines stay on the test”, are you curious about other types of lines in the home pregnancy test?

Here are the most popular types in the design of a kit test:

  • Indent lines: these are colorless or white sometimes, which stay in the middle or are spaced not evenly with the control one. Although the indented line may be confused with a positive sign, it is normally the antibody strip.
  • Dye runs are the smudged marks appearing at the location of a right test line, which are the false ones. On the contrary, a true test line is solid. When the dye runs show up, it means the results are not reliable.
  • Disappearing line: This phenomenon will happen when the dye has not properly flowed over the strip yet. The mark is solid, colored, and invisible after some minutes or a few hours.
  • True positive test result: As mentioned before, it’s time you waited for a pregnancy angel number and prepared for the newborn. Can a positive pregnancy line disappear? Unlike the EVP, it never fades.


How To Prevent Evaporation Lines?

Here is the fundamental knowledge and advice for you to have an accurate process of testing at home. Do evaporation lines disappear?

No, but you can reduce the chances of it showing up.

When you find out that you have become a mother is considered to be the most meaningful moment in life.

Thus, prepare well before using the kit test to get an accurate reading and the best result.

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