45 recommendations for 3D printed audio-tactile graphic design

• Planning

  Here you will find information about what you need to understand and keep in mind before producing the graphic. This category includes general, audio, tactile and audio-tactile recommendations.

  • General

    • PG.1

      Involve visually impaired people and educators in the design and development phases.

      • They can act as users, testers, consultants, informants or collaborators, for example.
      • Examples of techniques involving people: observations, interviews, diaries, collaborative prototyping, co-design.

    • PG.2

      Prioritize the development of graphics whose real objects are not easily found, are inaccessible or rarely covered in the curriculum.

      • Examples: large or architectural objects, representations of minorities or ethnic groups.

    • PG.3

      Predict which are the graphic main points so that the concept is understood, during your planning.

    • PG.4

      Keep elements consistent across different graphics, especially if they are part of a set.

      • Tip: avoid changes in the tactile elements layout, shape and position, as well as the verbal terms used.
      • Examples: buttons are always in the same position, the same scale is used.

    • PG.5

      Explore playful and thoughtful graphics with children.

      • This encourages their engagement and access to symbolic representations.
      • Examples: different tones of voice, smells, games, fitting pieces.

    • PG.6

      Prefer audio-tactile graphics that are easily transported.

      • In some cases the graphics may not be portable, depending on the context and pedagogical objective.

    • PG.7

      Stimulate senses other than touch and hearing for complementary interaction, if possible.

      • Examples: smell, taste, vision.

  • Audio

    • PA.1

      Use sound resources in addition to speech.

      • Examples: music, playful sounds, environment sounds, animal sounds, sound effects.

    • PA.2

      Make the verbal description simple, objective and with everyday words. However, do not suppress relevant information or fail to use correct terms and appropriate technical language.

      • Do not underestimate the blind student comprehension ability, but respect their development and learning potential.
      • Tip: adjust the description based on previous knowledge, cultural context and even other languages, if necessary.
      • Tip: if you have difficulties communicating information, ask blind people for help.

    • PA.3

      Consider that the audio description has the role of informing and mediating the student's exploration, not of interpreting the object for him. However, there is no neutral language, nor translation without intermediation.

      • The audio should allow the student to find their own emotions, sensations and interpretations.
      • Be aware that your subjectivity is present in the material, but that the right to interpret the content belongs to the students.

    • PA.4

      Allow the blind student to have sound information control during the interaction.

      • This means that it should be possible to turn the audio off and on, forward or rewind the audio, adjust audio speed and volume, for example.

    • PA.5

      Provide audible alerts in case of errors that interrupt the graphic operation.

      • Be careful as too many interventions can discourage the student from continuing to explore.
      • Tip: redo or modify the graphic if too many interventions are being triggered.

    • PA.6

      Use voice commands as an alternative to activating audios, as long as it does not interfere with the blind student's experience or interpretation.

      • Tip: implement a keyword or button that will recognize the command, if used. This prevents accidental activations.
      • Examples: commands like “more info”, “what’s this?”, “save info”.

  • Tactile

    • PT.1

      Consider that there is no single correct exploration of the audio-tactile graphic, as it depends on the context of application and pedagogical objectives. However, some postures and hand movements are frequently used in tactile exploration.

      • Postures: (1) Grasping: holding the graphic with one hand and exploring with the other; (2) Stabilize: use one hand to fix the graphic on the table and use the other to explore; (3) Diverging: exploration with two hands in different elements; (4) Converge: exploration with your hands in a single element.
      • Movements: (1) Feel: feel the graphic’s textures and shape; (2) Measure: use of hands to approximately measure the tactile element’s size; (3) Compare: compare two tactile elements to check if they represent the same concept; (4) Count: count of the same tactile elements in the graphic; (5) Communicate: indicate, explain or inquire about the graphic. The movement can be to feel the image as a whole or elements individually.

    • PT.2

      Explore different tactile elements to accommodate the blind student's needs, but prioritize familiar symbols.

      • Consider that the entire tactile surface must be accessible to be explored and reached by the fingers (except for object representations with holes).
      • Tip: if you need to differentiate equal elements, use different sizes.
      • Examples: points, symbols, geometric shapes, lines, dashed lines, arrows, areas, textures, geographic north, spatial references.

    • PT.3

      Simplify the tactile surface by removing small details or decorations. Consider that tactile information should be simple, clear and salient, without redundant information or exaggerated details.

      • Simplification should not mischaracterize the represented object, so keep characteristics that refer to the real object.
      • Tip: if you want to show these details, make another graphic on a larger scale.

    • PT.4

      Do not make graphics that are perspective representations or with overlays.

      • If the visual reference (image) is in perspective, the tactile surface must be modeled with a frontal and/or side view.
      • If the perspective is part of the object or learning context (art, for example), do not change the representation.

    • PT.5

      Use Braille to convey complementary or equivalent information to audio recordings.

      • Tip: observe the context used to decide whether the use of Braille is necessary.
      • Examples: Braille in titles and markings to complement the sound information; Braille available with the same content covered in the audio.

  • Audio-tactile

    • PAT.1

      Consider that tactile and sound information are complementary to each other.

      • Tactile information better represents spatial relationships such as dimensions, shape, volume and textures.
      • Sound information better represents descriptions such as colors, facial expressions, historical aspects, sounds and examples.

    • PAT.2

      Value for visual, auditory and tactile aesthetic quality.

      • This is beneficial for the social and cultural inclusion of blind students.

    • PAT.3

      Design the graphic so that sound information is easy to add or change, and easy for blind students to access.

    • PAT.4

      Insert markers to indicate points with audio.

      • These markers must be easily detectable, but must not significantly alter or distort the tactile surface, so as not to be confused with tactile elements of the graphic.
      • Tip: use buttons in different formats as an auxiliary component to activate audios, or to turn the function on or off.

    • PAT.5

      Determine a specific action for the audio release to prevent accidental activations. Choose tactile gestures that are already familiar to blind students.

      • Activating an audio must be the result of a definitive action.
      • Examples: familiar tactile gestures used in smartphones or natural gestures of tactile exploration, such as pointing, scanning with the index finger, tapping once, twice or three times, pressing, brushing, pressing or tapping on a point for 1 second.

• Materials and Production

  Here you will find information on the use of resources (such as 3D printing) and the audio-tactile graphic design and manufacturing process. This category includes general, audio, 3D modeling and 3D printing recommendations.

  • General

    • MPG.1

      Keep the process simple or give non-expert people the tools they need to develop the graphics.

      • The technology must be robust and low-cost, facilitating the empowerment and autonomy of educators.

    • MPG.2

      Divide a detailed or larger object representation into parts.

      • This means creating multiple audio-tactile graphics to represent a single object.
      • Tip: create a smaller, simplified graphic that represents the whole.

    • MPG.3

      Use tangible and moving parts when possible.

      • This increases the blind student’s interaction with the audio-tactile graphic.

    • MPG.4

      Create a virtual library of ready-made graphics or standardized tactile elements that can be reused in different projects.

      • Tip: store and share projects online to other educators, makers and communities. Preferably, promote free and public digital sharing with open licenses.
      • Examples: animal shapes shared with a Creative Commons license, copyleft or OER.

  • Audio

    • MPA.1

      Integrate the 3D printed tactile surface with electronic devices to create audio interaction points.

      • Devices must be made available to students if they do not have access.
      • Tip: give guidelines on its use.
      • Tip: conductive materials can be used to create interaction points, such as 3D printing conductive filament or conductive ink.
      • Tip: low-cost electronics, tablets, smartphones and computer vision are alternatives for adding audio to the tactile surface.
      • Examples: Near Field Communication (NFC) tags, capacitive sensors, Arduino electronic boards, Raspberry Pi, proximity sensors, applications, touch screen, cameras, QR Code recognition.

    • MPA.2

      Avoid overwhelming the student with sound information all at once. Prefer to record multiple audio tracks under two minutes rather than a single long audio.

      • Tip: select the most relevant information about the element you are describing.
      • Tip: make audio tracks with different levels of complexity or type of information, which are accessed by different gestures.
      • Examples: one tap on the element and the student receives its name. Two taps, there is a brief explanation.

    • MPA.3

      Consider including headphone jacks.

      • This way the blind student can focus on sound information without distractions.

  • 3D Modeling

    • MPM.1

      Explore different tactile surface options, which can range from just relief to three-dimensional (3D) objects.

      Tip: prefer 3D graphics, closer to the real object.

    • MPM.2

      Work on modeling the tactile surface to scale, but avoid representations that are too large or too small.

      • The representation is very small if it is smaller than the finger phalanx and very large if it goes beyond arm’s reach.
      • Tip: note that the Braille cell has a standardized size.

    • MPM.3

      Modify 3D digital models or use pre-existing databases to create your graphic, if available.

      • Examples: 3D models on sites like Thingiverse, NIH 3D Print Exchange, NASA 3D Resources, APH Tactile Image Library, National Library of Medicine Visible Human, geographic databases like OpenStreetMap, GIS data.

    • MPM.4

      Use 3D scanning as an alternative to acquire faithful digital models of the real object.

      • Tip: combine with other types of modeling, handmade or digital.

  • 3D Printing

    • MPP.1

      Use 3D printing supplies like PLA, ABS and/or resin. Combine with other materials or manufacturing processes such as laser cutting.

      • Tip: explore materials to create different textures and define what works best in the context of use.

    • MPP.2

      Consider the 3D printer limitations and characteristics and adjust the printing parameters to avoid imperfections.

      • Tip: divide the digital model into several parts to be printed, if necessary.
      • Tip: watch for possible imperfections that could be confused with textures or image components.
      • Tip: post-process the 3D printing if necessary. The tactile surface must be safe for the person handling it. It should be smooth to the touch, neither too rough nor too smooth, without sharp edges, non-flammable and non-harmful.
      • Examples: maximum print size, available supplies and post-processing needs.

• Context, Use, and Inclusion

  Here you will find information on student and educator’s interaction with the graphic.

  • CUI.1

    Always offer accessible learning materials that are equivalent to those offered to sighted peers. Provide full participation possibilities for blind students to share knowledge with peers.

    • The learning materials must address all the content worked in the classroom.
    • All accessible materials need to be ready before the start of activities or classes.

  • CUI.2

    Seek the inclusion of students with other disabilities so that they can also benefit.

    • Example: describing or adding color to the graphic is meaningful for blind students and includes low vision and sighted peers.

  • CUI.3

    Recognize that each student brings a different set of knowledge.

    • Blind students bring experiences from their non-vision, for example.

  • CUI.4

    Ensure use independence and content interpretation to the blind student.

    • Tip: instruct students on how to read the audio-tactile graphic if it is their first time.
    • Tip: leave a tutorial available at all times if needed.

  • CUI.5

    Use self-explanatory graphics and materials whenever possible.

    • The presence of a tutor or educator can help contextualize the topic and clear up doubts.
    • Promote autonomy and equality of conditions for blind students.
    • Tip: enable the blind student to identify the graphic correct position and find the starting point, if any.
    • Tip: add audio commentary to contextualize the blind student if needed.

  • CUI.6

    Present a simplified graphic first, and increase the detail level as the student develops in the topic.

    • Tip: this is just one of the possible teaching strategies. Observe the context.

  • CUI.7

    Allow the blind student to use both hands in tactile exploration.

  • CUI.8

    Use do-it-yourself methods as a strategy to encourage peers and teachers' involvement in the practice of inclusive attitudes. However, it shouldn't be a rule.

    • It is important to value the professional who designs the graphics, in the same quality as those made available to sighted students.
    • Tip: encourage visually-impaired colleagues to help with verbal descriptions. This experience is enriching and will give them a better perception of the surroundings and cooperation, in addition to helping their ability to concentrate.
    • Examples: students recording their own audios, teachers learning and developing their own 3D prints.

  • CUI.9

    Reuse the graphic for other pedagogical purposes and contexts.

    • Tip: one way to do this is to change audio descriptions, but keep the same tactile surface.