Subscription payment issues

We do not handle subscriptions, have access to your credit card information, or process transactions or refund payments. All of these matters are handled by Apple. If you have any payment-related issues, please contact Apple. Thank you.

RPaintPro has a subscription but it can not be restored on the device

Restoring purchases is handled directly by Apple. When you can not restore a purchase, usually you are using a different Apple ID on the device and this ID does not include the subscription. Check/correct the Apple ID and try again.

Problems accessing the Photos on the device

Our Apps use the Apple standard protocol to access the Photos. This means that you may have some settings wrong on your device:

• You may have denied the Photo access authorization request of the App
• You may have some Restrictions enabled on your device.

In the first case, you have to enable the App to access your Photos:

1. Open the Settings from the Home screen on your device.
2. Tap RPaintPro/RealPaint/RPaintLite (at the bottom where all apps are listed).
3. Tap Photos → set “Read and Write” (the Apps read only, there is no writing to the library).

If this it is still not working:

1. Open the Settings from the Home screen on your device.
2. Go to Privacy in the left panel.
3. Make sure that Photo is enabled for the App specifically.
4. Restart the App.

In the second case (if you don’t see the Photos after tapping RPaintPro/RealPaint/RPaintLite in Settings):

1. Launch Settings from your Home screen.
2. Tap Screen Time. Is it Turned on?
3. If yes, Tap Content & Privacy Restrictions. Is it on?
4. If yes, tap Photo and allow modifications.
5. Restart the app.

The app is installed but it does not start

This happens when you have too many apps installed and running, so the memory is not sufficient. You should stop and delete some apps to free memory space.

Sometimes RealPaint gives me hundreds of drops/parts of paint, normally of the white paint. What do I do with a recipe that I cannot apply?

It is not due to a program error, but to a physical fact. Some light colors require a certain chromaticity that can be obtained by mixing paints with the appropriate properties of the color strength. Furthermore, in order to have the right final color, it is necessary to add a lot of white to overcome the color strength of the mixed bases. For this reason, the program provides recipes according to the increasing overall drop count, being, therefore the first most “economic” recipe. In case white paint is required in a great amount, the remaining part of the recipe needs to be mixed first, and then added, a little at a time, to the quantity of white that you wish to use effectively. Having to mix only two colors is an easy way to get the final color right. From this point of view, it is good to know that wet acrylic colors are usually lighter compared to when they are dry. Therefore, in the final mixing phase it is recommended to check on paper whether the mix is too dark and add more white if needed.

One of the parameters in RealPaint is the chromatic error allowed between the target color and the recipe. Why is it set to 2 DE*94 and what happens if I set it to 0?

RealPaint is able to calculate recipes also with zero error but this requires very precise pigment ratios. This precision collides with various practical aspects: 1) The number of drops/parts resulting from each base can be enormous; 2) The physical dimension of the drops (or parts squeezed from tubes) is different from eye dropper to eye dropper (or it depends on the paint consistency which can be different from tube to tube, according to the physical properties of the pigments) and changes with the evaporation of the solvents; 3) The calculation of the recipes is based on the Color Matching Functions defined by the CIE (standard observers at 2 degrees) which differ from the color sensibility of every individual; 4) The parameters of the system have been obtained through measurements that have their own innate errors; 5) The lighting spectra are standard and certainly differ from those real ones used, at least where the illumination strength is concerned; etc. Considering all these variables, we have observed that the error set to 2 practically provides more valid and useful recipes. If the mixed color is not exactly the desired one, also due to the unique eye of the painter, it can be easily adjusted manually because the color suggested by RealPaint is in fact very close to the target color. From this point of view it is important to understand that an error of 1DE*94 is roughly the threshold for perceiving two fields of adjacents colors as different. Errors up to 3 among non-adjacent colors in a picture are invisible to anyone because the human color perception depends heavily on the surrounding colors!

When I start from RGB values of a photo, I obtain colors that are too dark. Why does this happen and what can I do to have the right recipe?

The first thing to look at is that the white point of the monitor must be set to 6500K. Then, you have to remember that the monitor emits light while the painting reflects it. Therefore, if the light is not strong enough, the perceived color of the picture will be darker than the color seen on the monitor. A very similar thing happens when one paints outdoors, for example under the sun, and then returns to the studio realising that the picture seems too dark.

When I mix a color by hand, it seems identical to the color of an object or an image. When I photograph the object or the original image near the mixed color, why do I see a difference between the two colors that I otherwise cannot see in reality?

It is because of a phenomenon called “observer metamerism”. Practically, everyone’s eyes convert the full spectrum of colors into electrochemical signals through a type of receptors called cones. Tristimulus color theory, which explains our color perception, stems from the hypothesis (Young in 1802, following others’ studies from 1777!) that the human eye has three different types of color sensitive receptors (cones). Cones are extremely sensitive to light and can distinguish among different wavelengths. The three type of cones respond to different wavelengths of light emphasizing the short wavelengths (blue), medium (green) and long (red). The sensibility curve is individual and varies from person to person. Normally we do not notice this difference, except in pathological cases like color-blindness, because we are unable to see through other people’s eyes and because our eyes/brain compensate for the average light as they do for the average hue. These sensibility curves were first noticed in the late 1920s. The XYZ color space (based on direct measurements of the human eye response) was derived from a series of experiments conducted between 1928 (Wright) and 1931(Guild) involving 17 people (a very small number of human observers of nearly a century ago which still is the main reference today!). It was also one of the first mathematically defined color spaces created by the CIE (an international committee for the establishment of color standards) also known as CIE XYZ color space. The operation of many digital cameras (and also the RealPaint) is based on these curves. When two colors, that seem identical to us, have been obtained from different colorants, their spectra differ in reality. This is why color perception varies from person to person, that is from person to camera as the various spectra through different sensibility curves cause various tristimulus perception. On the other hand, the various spectra may give identical tristimulus values. This is why RealPaint manages to give various recipes for the same target color despite the spectral difference from recipe to recipe. These various recipes provide the same color perception perceived with sensibility curves equal to the standard observers’. Upon changing the observer, the recipes may create a different color perception. The only way to have the same color perception between two different samples for everyone and for cameras is to have the same spectrum for both samples. Obviously, same perception in this case means that everyone will see that the two samples have the same color, but the individual perception will vary from person to person due to the individual filtering by our eyes resulting in a subjective conversion into tristimulus coordinates.

I have finished the white included in the RealPaint recipe. May I use the white of another brand that I have?

White is a paint base just as any other paint base. Even if it is placed in the achromatic zone in the color spaces, it has its own color strength and a very strong chromatic influence on the trajectories of the mixed colors. The most opaque and common white today is the Titanium White. Normally, the suppliers have a white that uses titanium dioxide because of its particular physical properties, but the crystal structure of dioxide and its treatment may vary. Moreover, the ratio between the amount of pigment and the solvent differs from brand to brand. Therefore, it is not possible to substitute a white with another white directly. In these cases, you can try to mix the part of the recipe without the white and add your white afterwards adjusting the quantity by hand and correcting the potential chromatic variations.

It seems to me that the color of the paint changes when I add a final transparent coating or fixative. Does it have to do with perception or is there an actual chromatic variation?

Light crosses the layer of transparent paint film (that acts as a light filter) and the spectrum of the perceived light contains both the film and the paint beneath (with the light bouncing back and forth in the transparent layer depending on the refraction indexes). The combination of the two is perceived as just one color by the eye. This means that there is a real difference in the reflectance spectrum and, therefore, in the color perception. This is one of the reasons why this system does not provide accurate recipes for very dark colors. At this point, with the low lightness of the paint, the spectrum is more related to the property of the film surface reflection than to the pigments, exactly what happens to glass with some black object behind it (when one can see the glass reflection but not the black object).

Are there transparent paint lines in RealPaint, like watercolors?

No. Transparent paint provides a color perception that is born from the interaction of light filtered from the color film and the support (paint background surface) that appears partially visible. RealPaint does not have any information on supports (canvas, paper, cardboard or else) or on the layering order of paint, but takes into account only the chromatic responses of the paint bases assuming a complete opacity. Note, however, that when a transparent color is mixed with an opaque one, an opaque color develops. For this reason, various transparent colors have been included in this system, but opaque ones still need to be used in each mixture. Otherwise, the color in general is not going to be the same as the target color and the computed recipes will not be valid.

The mixed color differs from the target color

We carefully check the paint parameters and we use them in RealPaint only when they are all measured and are very accurate. However, there can be many cases when the mixed colors don’t match the target color:

1. The paint amounts are not measured correctly by the painter.
2. The tube/jar is old or was open for a while and solvent has evaporated.
3. The tube/jar was on a shelf long enough to have pigment/medium separation. In this case the tube has to be emptied completely and mixed well!
4. The paint manufacturer changed the pigment or the medium, or the pigment to medium ratio. This makes RealPaint useless with this paint base. The only solution is to deselect it in RealPaintPro and not to use it anymore.

In cases 1 and 2 the solution of the problem is simple. The recipes usually include 4 bases, or even less. If the mixed color has a wrong dominant color, it’s often easy to change the amount by eye, because the bases to mix are correct, just the amount of some bases has to be tuned.

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Disclaimer

This software is provided on an “as is” basis without warranty of any kind, expressed or implied. Under no circumstances and under no legal theory, whether in tort, contract, or otherwise, shall AI4res s.r.l. be liable to you or to any other person for any commercial, indirect, special, incidental, or consequential damages of any character including, without limitation, damages for loss of goodwill, work stoppage, computer failure or malfunction, or for any and all other damages or losses.

Please note that color of paint coming from various parts of a tube/jar or from different batches of the manufacturer can vary, so mix small amounts first to be sure that computed recipes meet your needs!