KRITA 4.4.3 ANSWERING YOUR QUESTIONS: PPI, CMYK, RGB, Bit-Depth, Raster and Vector images.

Hello everyone,

In this week’s tutorial, you are going to learn a lot.

I am specifically answering your questions: PPI, CMYK, RGB, Bit-Depth, Raster Vs Vector images.

What are they? What do they do? How to choose?

This video was made following your comments and questions on my different social platforms. I understand your confusion and I hope this video will answer all your questions.

Also, I have added four updates from last week’s video. If you didn’t watch last week’s video, please feel free to skip this first part. The video’s tutorial starts at 02:32.

Chapters

00:00 Introduction

00:29 What I forgot to mention: # 1 - Creating a text, creates automatically a new vector layer.

00:59 What I forgot to mention: # 2 - Changing the font size.

01:26 What I did not know: # 1 - Adding new fonts to Krita.

01:48 What I did not know: # 2 – Kerning toggle is not working properly.

02:32 Understanding the basics of image resolution and color modes.

03:11 How do I set my image resolution? (showing you how + advice).

04:08 Color mode: Which one should I use? CMYK (why to use it and what it does).

05:06 Color mode: Which one should I use? RGB (why to use it and what it does).

05:47 So… Which one should I use?

06:02 What is bit depth and how to set it? Watch as I give detailed information and show you the formula used in software to calculate how many tones you will get.

06:56 Which one should I use? (bit depth).

08:15 Slide showing you the settings I use for my image resolution, color mode and bit depth.

08:24 Deciding which image to create: RASTER IMAGES VS VECTOR IMAGES.

09:15 What is a raster image?

10:40 What is a vector image? Explaining how it works. This will be interesting if you were wondering…

12:08 A quick comparison. Comparing a raster image and a vector image.

12:30 Pros and Cons of Raster Images.

13:01 Pros and Cons of Vector images.

13:35 Conclusion and introduction to next week’s video.

As always, be sure to let me know if I forgot anything or if you don’t agree with my explanations. I am neither a computer expert nor a software engineer. So, I’ll be happy to learn from you. Thank you in advance.

https://youtu.be/G6vGLK600KM

4 Likes

Hi @CelticCoco

You’re swimming in deep waters now :slight_smile:

As usual, your production and presentation standards are very high and as usual there are some comments I’d like to make:

2:25 Reporting the Kerning toggle bug. You can make a formal bug report at https://bugs.kde.org/ (sign up and sign in are needed). This is always a fun filled activity.

3:20 Setting ppi resolution. This entire area causes a lot of confusion. The ppi resolution has no meaning and doesn’t matter unless you intend to print the image. In that case, you need to specify the Width and Height in inches (or cm), not pixels. The Width and Height have a choice of units in the drop down boxes to the right.
The ‘resolution’ of the image is solely determined by the size in pixels.

4:10 CMYK vs RGB This is a very complex subject area. If a client says that they want you to deliver a CMYK profile image then you need to ask them to provide you with (or specify) the .icc colour profile that their printing process uses. That’s just the start of the complexity and you need to talk to someone who’s an expert in that area.

7:12 8-bit images. An 8-bit RGB/A colour image has 8 bits assigned to each of the R,G,B,A channels and so the colour (RGB) has 24 bits which gives over 16 million possible colours, each colour at a possible 256 different opacity values.
There are some good technical reasons for using 16-bit integer when creating a multi-layer image that has wide area gradients and/or non-normal layer blending modes but for most purposes the 8-bit RGB/A is good enough.

Hello there. Thank you for letting me know where to go to report the bugs. I shall do that today.

Regarding this video, I had to peel off a lot of technical and complicated information. Remember, Ahab, that my channel focuses on beginners and intermediate levels in digital art. If I talk “techy” with them, I will lose them as they will be overwhelmed. So, I give them the most important information they need to continue their journey into the digital world.

I hope that with time, they will come to a point when they will ask themselves more technical questions and that they will investigate that.

Maybe I should put a disclaimer at the beginning of some of my videos, that the information that they are about to get is basic, or not too technical… or something like that.

That said, I DO NOT KNOW everything. I am also learning as I go.

So, thank you for all the information you just gave me today. As always, I learn so much from you.
YOU ARE THE BEST!!!
Big hugs and have a great week.

Some notes after seeing the video:

  • in vector you don’t have weaker colors… pixel and vector share the same color space so the same color are available too both.

  • it is CMYK that has less colors available compared to RGB not vector. you get that impression because vector is preferred for printing because it does not loose scale and then CMYK is used for the print.

  • For pronouncing depth you really need to say the P of the word or it will sound funny. de-PE-th.

  • overall the script seemed to going a bit back and forth until you reached the final stages where you layed the ground work. also when placing the images of the color spaces the points are random where confusing not to mention you did not explain the WHY they are used in each medium just where they are used. When you did the dots you could have explained that.

  • Also using CMYK does not make you a professional there are professionals that work in other color spaces due to their medium.

No, vectors are sRGB only (and then converted to the document color space). Saying “colors are weaker” is still not correct, though, although one can say that the gamut is smaller than it could be if you’re using a wide gamut color space for the document… So the visual difference you see can be exactly that, weaker colors on vectors.

That part is really important! @CelticCoco the beginners often think they should paint in CMYK; I had a user like that just today: https://www.reddit.com/r/krita/comments/na47lp/issue_with_darkmultiply_blend_modes/ - but you shouldn’t paint in CMYK. There is no advantage, practically. It gives you bad color math, weird blending modes, the gamut is smaller than sRGB, and in most cases you won’t even achieve correct colors anyway.

The most complicated/“professional” workflow is as follows:

  • create RGB document → set up CMYK soft-proofing with correct CMYK color profile → finish painting → convert to the correct CMYK color profile. Note: you also need to have a display calibrated and set up correctly in Krita.

Less professional, easier for beginners:

  • create RGB document → set up CMYK soft-proofing (best: use correct color profile, worse: just use Chemical Proof available in Krita by default) → finish painting → just send your work in RGB to the printer or printing company. You can just use somewhat-sRGB display here, unless it’s wide gamut, the differences won’t be too big, I guess.

Easiest:

  • just stick to RGB.

If you create a document in CMYK Chemical Proof thinking that it will improve your life in any way, you’re going to be very disappointed. 1) This is most probably incorrect color profile, so the colors will look wrong when printed out. Or there will still be a conversion done (if your printer or printing company is not terrible), which means there is no point in starting from CMYK… 2) Even if it was a correct profile or if you use a correct color profile, there is a high chance that if you want to print it in a different company or on a different printer, you’ll need just another color profile, which will lead to more color quality loss. Meanwhile you could’ve just worked on a bigger gamut, sRGB (sure, typical CMYK has some colors that sRGB doesn’t have but it’s generally a bit bigger - plus is suitable for showing it off of the internet and is easier to work with…) or maybe even bigger (though then you’d need bigger bit depth too).

So, the non-technical easy answer for beginner would be “just use sRGB for all your work”.


@CelticCoco another mistake you’ve made in your video which is very common among beginners is to talk about ppi while not talking about the size in inches. If you just change the number in the box you highlighted, nothing will change (as long as the other two numeric boxes are set to pixels). The equation is as follows:
pixels = ppi * inches (in one dimension).
And Krita and digital art in general only cares about pixels. If you make the ppi = 1000000000 without changing the number of pixels, the document size in your folder or the memory it takes in Krita will be the same as if you put ppi = 1. It only matters when printing, because it tells the printer “please put this many pixels in this big of an area”. You can also use this number when you create an image and want to see how much it will take when printed - so, for example you want to have a document 10x7 inches with good printing quality, then you set up Krita document to be 10x7 inches with 300 ppi. But if you define the canvas size in pixels, changing ppi won’t change anything.

It’s very common because there is plenty of misinformation about it around the internet, too, even very professional-looking educational websites. I know it might be confusing, especially when the word “resolution” can be used in a few contexts that give it different meaning. Like, you can have resolution in pixels or resolution in ppi…

Thank you for teaching me something I didn’t know. This is why I ask people to correct me if I am wrong. I will make sure to update the information to my viewers, as always.

Now, please allow me to respond to a few things.

First, regarding the fact that I am not explaining things well. Thank you for pointing this out. Teaching is not something easy, as many may think. However, I do everything I can every week to make my tutorial 1% better. So, inputs and advice like yours are very helpful. Again, thank you. Greatly appreciated.

Second… Please remember that my audience is made mostly of beginners. I don’t want to overwhelm them with technicalities. Before becoming the humble and unknown illustrator that I am, I was a molecular biologist for 15 years. I work in cancer research first, then was hired by a new team that worked on HIV-1. I trained a large number of lab technicians and learn very quickly that when you bombard people with tech words too fast, they panic and want to give up. So, I am being very careful here.

Third. I didn’t think I said that working with vector made anyone professionals. Maybe I got lost in translation. I tried to say the people who mostly work with that type of image are professionals. I’ll have to rewatch… Thanks for noting that.

And lastly, I appreciate your help with the phonetic lesson. However, I am a lost cause. I have tried over and over, and my husband (who is American) says that I still sound like saying “DEATH”. So, maybe I should just try to avoid saying that word.

Have a great end of your day.

Wow. THANK YOU!!! Also, please see my reply to EyeOdin.
I will make sure to tell my viewers about all this new information.
MERCI! :heart: