Why touch matters
A digital exhibit usually relies on sight, and often on sound. For a blind or low vision visitor, touch can be a primary way of understanding shape, size, texture and structure. A tactile alternative is a physical stand-in for something that would otherwise be viewed on a screen or behind glass: a model of a building, a replica of a small object, a raised version of a map or diagram, or a handling collection of items that visitors are allowed to pick up.
Touch is not just a substitute for people who cannot see. Many sighted visitors, including children, enjoy handling things, and tactile material can improve understanding of how something works or fits together. It can also give pleasure and a sense of presence that an image cannot.
Types of tactile alternatives
- Replicas and models. A scaled or full-size copy of an object, made in a durable material. These allow touch where the original is fragile or valuable. The digital steps involved, such as 3D scanning, can help to make accurate copies, though a scan alone does not make a good tactile piece.
- Raised-line and relief graphics. Maps, floor plans, timelines and diagrams produced with raised lines, textures and shapes. A relief map of a landscape, for instance, can convey slopes and water in a way that text cannot.
- Texture samples. Small pieces of material, such as different fabrics, stones or woods, that illustrate a process or a type.
- Handling objects. Real items, often common ones, set aside for use. These are usually separate from the main collection.
- Tactile floor and wayfinding elements. Textured paths, raised signage and tactile maps of the gallery layout help visitors find the exhibit in the first place. See gallery wayfinding.
- Tangible controls. Physical objects that start media when placed or moved, as in tangible interfaces, can be useful if they are labeled by touch as well as sight.
Designing a good tactile piece
Touch reads information more slowly and in smaller portions than sight, so a tactile piece should be simpler than the image it replaces.
- Reduce detail. Copying a complex picture exactly usually produces a confusing mass. Pick the main features and leave out the rest.
- Make shapes clear. Edges, ridges and changes of height need to be distinct and large enough to feel. Fine detail that disappears under a fingertip is wasted.
- Use consistent conventions. If a raised dotted line means a path in one piece, it should mean the same in another. A key placed in an easy-to-find position helps.
- Choose materials with care. Smooth, warm and durable materials such as wood or certain plastics are common. Avoid sharp edges, splinters, rough burrs and anything that could harm skin. Think about temperature, since cold metal can be uncomfortable in winter.
- Orient it. A clear starting corner, a standard orientation and a stable mount keep a piece from being turned the wrong way up.
- Scale it sensibly. Models should be big enough to explore with two hands but small enough to reach comfortably, and positioned in line with the guidance on reach ranges.
Braille labels are helpful for those who read braille, but many blind visitors do not, so do not depend on braille alone. Large print and audio are useful companions. Check the braille with a qualified reader or transcriber, because errors are common and spelling or contraction mistakes are easy to miss.
Combine touch with audio and screens
A tactile piece is more powerful when it connects to other media. Exploring a model while listening to a description tells the visitor what each part is and why it matters. Audio description can be triggered by a button next to the model, or played from a handset, and audio guides can include stops that direct people to tactile stations. Some exhibits use touch sensors on the model to start narration for the part that is touched. Be sure that the sensors are reliable, and that the audio can be replayed.
Where a digital interface sits next to a tactile one, keep them in step. For example, a screen showing a rotating 3D object can be paired with a physical copy that can be held, so that sighted and blind companions can share the experience.
Care, safety and hygiene
Objects that are touched often need to be robust. Plan for wear and tear, sunlight, cleaning and replacement from the start.
- Choose materials that tolerate repeated handling and cleaning.
- Set a cleaning routine with products that do not damage the surface. The same approach used for shared screens, described under touch hygiene, applies.
- Secure models to a base or tether them if there is a risk of theft or dropping, without making them awkward to explore.
- Inspect regularly for cracks, loose parts and rough edges.
- Keep spare parts or a second copy where it is practical.
When original objects are handled, conservation advice is needed first. Some items can never be touched, and in such cases a replica is the right choice. The reasoning behind collection care and digital surrogates can help teams explain to visitors why some things are copied.
Involve blind and low vision visitors early
The best guide to what works is the experience of people who rely on touch. Invite blind and low vision visitors, and organizations that serve them, to look at early prototypes made of cheap materials. They can tell you whether a detail is readable, whether an arrangement makes sense and whether a description is helpful. Rough prototypes in foam, card or printed plastic cost little and can be revised quickly. Also ask what they would like to see in future: sometimes the most valued feature is not a model of the main object at all, but a simple map of the room.
Finally, tell visitors that these resources exist. Mention them on the website, on the gallery plan and at the front desk. A tactile model that nobody knows about is hardly accessible at all.