Topics to Digital Painting with GIMP

From GIMP GUI Redesign
Revision as of 02:40, 10 March 2016 by Americo.Gobbo (talk) (Work In Progress)
Jump to: navigation, search



This document is a draft project to related in short the topics and after to organize pages more concise.

GIMP and Graphical Arts

Graphical Arts - Wikipedia

Ways to use GIMP



Style & GIMP

Product Vision


Current Product Vision

What GIMP do not need really?


The main asset* features on GIMP to visual artists are probably the Colour and/or Brushes. Perhaps undoubtedly the Colour is the core of application, because all assets (photo, paint, illustration, collage, etc.) of Visual Arts have colour. (*) I need a glossary of the GIMP parts... ;-)



Work In Progress

  1. LCH GIMP 2.9.2 | - Elle Stone
  2. Adding better LCH support on GIMP 2.10 | Development Mailing List | Elle Stone
  3. Lab Mode on Photoshop

References about LCH

  1. Introduction to CIE Lab & Lch
  2. LAB Colour Space - Wikipedia
  3. CIELCH Introduction
  4. CIELUV and CIELCH (Cylindrical Representation
  5. Guide to Understanding Color Communication - Xrite (pdf)
  6. Designing Graphical Elements for Cognitively Demanding Activities: An Account on Fine-Tuning for Colors


  1. Check RGB to CMYK
  2. RGB - CIELab - CIELCh (Interesting, based in Flash)
  3. Color Interpolation - sRGB ... to Jch, Jab | Cool
  4. CIE Schemas and colour differences
  5. Old discussion... lch
  6. Saturation Mask Plugin - Photoshop (lch option)
  7. CIELch instead HSL mode layer - Discussion...

Colour History Swap

Improving FG/BG colours and the interaction with colour history

On GIMP we have the interesting short-cut to swap colours between Foreground and Background colours. For painting tasks this swap is very useful, mainly if we are using the colour parameter (paint dynamics). Seeing an old bug report (thanks Elle)... I think be useful open a short discussion around the new feature on GIMP 2.9.2:

Add color history to colors dialog

Is already present on GIMP a history of colours on the dialog to change the colours of FG or BG. The concept of history on GIMP is a bit different... and like is a kind of a secondary palette. But is also interesting to have an extension of this concept with swap of the history colours. MyPaint has a efficient concept of this feature. The history of colours is a buffer with the last 5 colours used.

Proposal Swap History Colours

  1. Create a secondary swap colours short-cut where is possible to have the last colours used on the canvas.
  2. To have on the GIMP preferences the possibility to choose the amount of colours.
  3. A dialog of history colours where the swap short-cut is recursive.

I have made a short video to show this feature on MyPaint. The feature has, by default, the key 'x' to access the colour history of the last 5 colours.

MyPaint History Colours Feature

Brushes - Edit and Creation Flows

Simplify the flow to create raster brushes

Interpolation stains to make raster brushes (.gih) in a easier way...

Preview Brush Presets

  1. Preview Brush Presets Brainstorming Doc

Redesign and new brushes of the default set [!?]

  1. Reference of redesign document idea
  2. Redesign brush set - ToDo



Are the assets or resources (binary or formatted text) that could be used as facility or to expand/organize the workflow tasks of the visual artist.

Redesign and new paint dynamics of the default set [!?]

Perhaps is interesting to create the author sets or technique sets to improve or to expand the current set. These sets could be promote directly by > [?!]

Tool Presets Bugs and flow problems

Bugs to edit presets

  • Tool Options dialog - define in short ...
  • Tool Presets dialog

Problematic flow to create

  • Tool Options dialog
  • Tool Presets dialog


Tools & Around

Tool Options Features Order

New order and classification of features

Suggestion how the options could be ordered and classified on Tool Options.

Ordering and classification, for instance, on Paintbrush. The asset and preset are the new entries.

  1. asset (preview, field name, edit link)
  2. preset - new entry (preview, field name, edit link)
  3. dynamics - new entry (preview, field name, edit link)
  4. mode blend
  5. opacity
  6. incremental flag
  7. size
  8. lock brush size to zoom flag
  9. aspect ratio
  10. angle
  11. spacing
  12. smooth stroke
  13. dynamics options
    1. hardness
    2. force
    3. apply jitter
    4. fade options
    5. color options



TOOL OPTIONS (jul 2012) New Order of features on Tool Options

Make an abstract of main objections, contradictions, reason why.

Toggle Modifiers & Usability

Increase/decrease size and hardness brush on canvas

Have a toggle modifier key to interact with the size and hardness brush. The size and hardness is controlled by of the device (mouse or stylus) drag, for instance, to right increase, to left decrease. The GIMP users can show or not the outline of brushes. Some users prefer to have only the pointer mode without the outline. In this case, with no outline, the toggle modifier key must enable also (preferable) the brush outline, while this key is down (this method is used by Krita. See the short video of the feature). In this way is possible to control better the increase and decrease.

Current 2.9 git master

Is possible to change the size and hardness via short-cuts:

  • Size - Bracket keys of keyboard, '[' to decrease and ']' to increase.
  • Hardness (Custom) - the shorcuts do not working Bug report


Dynamic Zoom

The current keyboard shortcut (+) and (-) or the wheel mouse are difficult to use in a painting session, mainly because on digital painting is common to use the graphic tablets.(1) Use the Zoom tool becomes a bit difficult while painting: every time you must to select the zoom tool, via tool box or via keyboard, and to reselect again the paint tool to continue the painting session. To have a feature, as we have in Krita/Photoshop and MyPaint, turns the tasks more friendly and with a minor step number to make zooms and to return the main task.

On MyPaint and Krita this feature have a identical behaviour, the zoom is enabled with Ctrl+Mouse Wheel and Drag.

1. Some tablets, more new, have devices that can be used to simulate the wheel of mouse. But this is not a rule... many people prefer the tablet more simple and not wacom to work. For example, some artists use simple or economic graphic tablets, because they are more efficient to drawing.

Paintbrush with eraser ability

To use the same brush to erase a stroke with a toggle short cut (recursive). In MyPaint and Krita is possible to use recursively the two tools using only the key 'E'.

To make this in the current stable and development releases we must follow this flow:

  1. To share the paint options between tools
  2. Change between the P or N key with Shift+E and again P or N (for instance)to follow painting/drawing.

The process that is possible is a bit unfriendly if I do a comparison with the flow with Krita/Photoshop and MyPaint. Have a toggle or recursive key to make this, it turns this action more easy and fast to execute. Imagine the users that are using a graphic tablet with GIMP... is necessary stops the action with paint tool, and to use the hand (left/right) to invoke the eraser, with Shift+E, and after again, 'P' or 'N' (for instance) key to follow using the paint tools.

I think that the 'Paint Options Shared Between Tools' works fine in many cases... but not to all. My suggestion, here, is to provide another option to have the eraser directly on paint tool. For me and many painters that are using MyPaint and Krita, this feature is working fine. See thread on mailing list - Some ideas and suggestions around digital painting on GIMP.

Brainstorming and ideas

  • A plug-in action (with a toggle key) to enable some blend modes on the paint tools to erase the strokes. For example, the paint tool with blend mode + foreground colour to erase the stroke/stain. I have tested with Addition Mode, with white colour as foreground and works fine to delete. The main question here is: we want/must eliminate a wrong stroke or many strokes (this is a simple task) or we need of the Eraser Tool to make actions more complexes? I am thinking that both flow options are important and convenient, but each of these depends what we are doing in each moment. Normally, during the paint sessions, we must to delete some wrong or undesirable strokes/parts.


  • Krita and Mypaint way - I've made a short video using Krita to exemplify the feature. The key 'E', by default, is used to enable the erase feature. On MyPaint the feature has the same behaviour and short-cut key.

Paint Tools improvements

Paint tool + Texture (raster)

Patterns/Textures on the GIMP

Which the differences and likeness between pattern and a brush (.gbr and .gih) on GIMP?

  1. Both are the resources to mark or make stains
  2. Both are based in raster images
  3. Pattern is used to emulate textures in different kind of techniques or
  4. To fill figures with textures
  5. Brush is used to emulate random textures, of natural properties or not of brushes in the real world.

Well, we can to think the patterns as brush very specific.

How works on Krita


Photoshop - Bob Chiu Steps Video link

Brush Texture Option Photoshop.png

    • Create a Pattern > save it on pattern library
    • Create a brush
      • New document (size x height), for instance with 256x256px;
      • New preset brush - on photoshop the brushes birth directly as a preset, interesting (Krita also).
    • Select the brush
    • Now Brush Options > [1]
      • The options is possible to control many aspects:
        • Spacing, Hardness Angle, Flip and Size;
        • Enable the Shape Dynamics (basically is a .gbr with gimp paint dynamics); > [2]
        • Enable the Texture and is possible to see the library patterns, the options of Texture are: > [3]
          • Texture Library (dropdown open manager), Invert (flag), Scale, Brightness, Contrast, Texture each tip (flag), Mode, Depth, Minimum Depth, Deep Jitter, Control (drop down flags).
        • Enable Transfer > [4]
          • Opacity Jitter or Flow Jitter

Proposal of the feature on GIMP


The tool more near of an ideal Brush with Texture features (similar to Krita or Photoshop) is the Clone Tool. Perhaps this Tool is a good way to build a new Tool.

The Brush + Pattern is basically a dual brush where the pattern is a kind of mask in background. Options need are:

  1. Colour: Is necessary to use the colour asset on... as a normal brush.
  2. Texture aspect: Is necessary to have a flag to choose between default and inverted.
  3. Source: Image and Pattern (texture). Image as source is interesting to control something very similar to impasto or smudge.
  4. Alignment: Registered and Fixed.


Paintbrush and Pencil with smudge ability (raster)

On GIMP, now, is possible to make this in two steps - first we paint something (Pencil, Paintbrush, Airbrush, etc.) and after, with Smudge tool, we make the blend the stains/strokes. Basically, this feature is the current Smudge tool + a Paint tool (2). Now, the Smudge tool has only the capability to blend the stains, using a brush. The stains that are previously created. With MyPaint brushes, is possible to have the smudge on their brushes, but the mark is a basically a circle (dab). In the ideal painting world, is interesting to have the raster brushes with dynamic stains. The .gbr and .gih brushes with paint dynamics)... have the result more richest that a smudge brush on MyPaint. Figure smudge brush with MyPaint Figure smudge brush with GIMP (via 2 steps: make stains with some paint tool and after with smudge tool blend them).

2. Is necessary to think the way to link smudge with a paint tool... for instance, for any or for a specific tool?

Others from Mailing List, Bugzilla and threads

  1. Paint Dynamic and Tool Preset Preview | Andrew Pullins
  2. GIMP Workspaces | Americo Gobbo
  3. To have the Alignment feature on Paintbrush and Pencil > to make texture on-the-fly directly of the stain brushes | Gustavo Deveze Video Deveze
  4. Digital Painting Color Wheel Wikipedia | Americo
    1. Standard digital Red/Green/Blue
    2. Traditional artist's Red/Yellow/Blue RYB color model
    3. Red-Green and Blue-Yellow opponent pairs