Objects: Physical Characteristics

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Up: Objects

Introduction

There are several important physical features of artworks that it is important to capture, including the size and materials that it is made of. The model allows for both being explicit in the model for these, as well as simply including a textual description. The explicit form is strongly prefered, however it is recognized that not all systems will be able to provide it.

Beyond dimensions and materials, the model allows for the description of parts of objects, and parts of parts. These parts can be thought of as objects in their own right, and thus have titles ("Left Panel" of a triptych), descriptions, rights, images, dimensions, materials, and so forth.

Dimensions

Dimensions are included in the dimension property, and consist of three primary pieces of information: the numeric value in value, the type of dimension (e.g. height vs width) in classified_as referencing an external vocabulary of dimension types, and the unit used to align the value with the real world such as inches, pounds or seconds. The unit should also be given from a controlled vocabulary.

For example, a painting that measures 16 inches wide, by 20 inches tall, could be described as given below. Note that the repeated unit is not duplicated in its entirety, just its URI given in the second dimension.

{
  "@context": "https://linked.art/ns/v1/linked-art.json", 
  "id": "https://linked.art/example/object/51", 
  "type": "ManMadeObject", 
  "label": "Example 16x20 Painting", 
  "classified_as": [
    {"id": "aat:300033618","type": "Type","label": "Painting"}, 
    {"id": "aat:300133025","type": "Type","label": "Artwork"}
  ], 
  "dimension": [
    {
      "id": "https://linked.art/example/value/6", 
      "type": "Dimension", 
      "value": 16, 
      "classified_as": [{"id": "aat:300055647","type": "Type","label": "Width"}], 
      "unit": {"id": "aat:300379100","type": "MeasurementUnit","label": "inches"}
    }, 
    {
      "id": "https://linked.art/example/value/7", 
      "type": "Dimension", 
      "value": 20, 
      "classified_as": [{"id": "aat:300055644","type": "Type","label": "Height"}], 
      "unit": "aat:300379100"
    }
  ]
}

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Dimension Statement

If the dimension text is not recorded in a way that is condusive to generating the full set, then it can be given as a LinguisticObject, classifed as dimensions by reference to aat:300266036, and the text provided in value.

The same object might have a dimension statement as below.

{
  "@context": "https://linked.art/ns/v1/linked-art.json", 
  "id": "https://linked.art/example/object/52", 
  "type": "ManMadeObject", 
  "label": "Example Painting", 
  "classified_as": [
    {"id": "aat:300033618","type": "Type","label": "Painting"}, 
    {"id": "aat:300133025","type": "Type","label": "Artwork"}
  ], 
  "referred_to_by": [
    {
      "id": "https://linked.art/example/text/23", 
      "type": "LinguisticObject", 
      "value": "The painting is approximately 16 inches wide, by 20 inches high", 
      "classified_as": [
        {"id": "aat:300266036","type": "Type","label": "Dimension Statement"}
      ]
    }
  ]
}

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Shapes

While some combinations of dimensions can give a sense of the shape of the object, it is also often useful to be more explicit about the shape. For example, a shield-shaped painting (perhaps due to being painted on an actual shield) would likely still only have height and width given. Without the additional information of the shape, it might be concluded that the painting is rectangular.

Shapes are given as classifications on the object. It is recommended to use one of the AAT shape classifications, such as aat:300247394 for shield-shaped or aat:300263817 for oval.

{
  "@context": "https://linked.art/ns/v1/linked-art.json", 
  "id": "https://linked.art/example/object/53", 
  "type": "ManMadeObject", 
  "label": "Example Oval Painting", 
  "classified_as": [
    {"id": "aat:300033618","type": "Type","label": "Painting"}, 
    {"id": "aat:300133025","type": "Type","label": "Artwork"}, 
    {"id": "aat:300263817","type": "Type","label": "Oval"}
  ]
}

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Materials

Objects are made_of different materials. The materials are the type of material, rather than the specific bits of matter and therefore can refer directly to external vocabularies. When possible, it is good to use this model, and combined with the parts model described in the next section, allows for a comprehensive set of information about which parts are which sizes and made of which materials.

For example, a statue made of marble could be described as below.

{
  "@context": "https://linked.art/ns/v1/linked-art.json", 
  "id": "https://linked.art/example/object/54", 
  "type": "ManMadeObject", 
  "label": "Example Marble Sculpture", 
  "classified_as": [
    {"id": "aat:300047090","type": "Type","label": "Sculpture"}, 
    {"id": "aat:300133025","type": "Type","label": "Artwork"}
  ], 
  "made_of": [{"id": "aat:300011443","type": "Material","label": "marble"}]
}

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Materials Statement

Similarly to dimensions statements, it is possible to describe the materials using a LinguisticObject classified as being about the materials of the object via aat:300010358.

{
  "@context": "https://linked.art/ns/v1/linked-art.json", 
  "id": "https://linked.art/example/object/55", 
  "type": "ManMadeObject", 
  "label": "Example Multi-Media Painting", 
  "classified_as": [
    {"id": "aat:300033618","type": "Type","label": "Painting"}, 
    {"id": "aat:300133025","type": "Type","label": "Artwork"}
  ], 
  "referred_to_by": [
    {
      "id": "https://linked.art/example/text/24", 
      "type": "LinguisticObject", 
      "value": "Oil, French Watercolors on Paper, Graphite and Ink on Canvas, with an Oak frame", 
      "classified_as": [
        {"id": "aat:300010358","type": "Type","label": "Material Statement"}
      ]
    }
  ]
}

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Parts

As described in the baseline patterns, one of the main modeling paradigms used is to separate parts of resources from the whole. Physical objects are particularly amenable to this, and allows reuse of the rest of the model as needed. The parts do not need to be physically separable without destroying the object, but do need to be objectively definable in terms of the matter that makes it up. For example, the arm of a sculpture could have dimensions and materials, but while an arch in a rock formation might have dimensions, it is not made of anything, and is thus not a part of anything.

Physical parts are given using the part property, and use the same ManMadeObject class as the entire object. The classified_as property can be used to be more specific as to the sort of part, in this case the support for the painting, which is in turn made of canvas.

The model does not have a separate parts statement to describe this in a human-readable way, as this is traditionally done using the materials statement as demonstrated above.

{
  "@context": "https://linked.art/ns/v1/linked-art.json", 
  "id": "https://linked.art/example/object/56", 
  "type": "ManMadeObject", 
  "label": "Example Painting", 
  "classified_as": [
    {"id": "aat:300033618","type": "Type","label": "Painting"}, 
    {"id": "aat:300133025","type": "Type","label": "Artwork"}
  ], 
  "made_of": [
    {"id": "aat:300015045","type": "Material","label": "watercolors"}
  ], 
  "part": [
    {
      "id": "https://linked.art/example/object/56/part/1", 
      "type": "ManMadeObject", 
      "label": "Canvas Support", 
      "classified_as": [
        {"id": "aat:300014844","type": "Type","label": "Support"}
      ], 
      "made_of": [{"id": "aat:300014078","type": "Material","label": "canvas"}]
    }
  ]
}

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Sides of an Object

While some artworks can be treated as two dimensional, as the only part of interest is the front of a flat surface such as a painting, drawing or photograph, there are many other objects where it is desirable to record information separately about the front and back, or any number of other sides.

This pattern allows separate identities for the recto and verso of a page, the obverse and reverse of a coin, in the same manner as the frame or canvas of a painting. The use of "aat:300133025" is important to distinguish between objects that should be treated as the complete artwork, and objects that are either parts of it, or those that it is part of. One might treat only the front part of a photograph as an artwork, but still record information about the back, such as an inscription, without implying that the inscription was part of the art.

{
  "@context": "https://linked.art/ns/v1/linked-art.json", 
  "id": "https://linked.art/example/object/57", 
  "type": "ManMadeObject", 
  "label": "Photograph of Example Artwork", 
  "classified_as": [
    {"id": "aat:300128347","type": "Type","label": "Color Photograph"}
  ], 
  "part": [
    {
      "id": "https://linked.art/example/object/58", 
      "type": "ManMadeObject", 
      "label": "Front of Photograph", 
      "classified_as": [
        {"id": "aat:300190703","type": "Type","label": "Front Part"}, 
        {"id": "aat:300133025","type": "Type","label": "Artwork"}
      ], 
      "shows": [
        {
          "id": "https://linked.art/example/VisualItem/5", 
          "type": "VisualItem", 
          "represents": [
            {
              "id": "https://linked.art/example/object/60", 
              "type": "ManMadeObject", 
              "label": "Example Artwork", 
              "classified_as": ["aat:300133025"]
            }
          ]
        }
      ]
    }, 
    {
      "id": "https://linked.art/example/object/59", 
      "type": "ManMadeObject", 
      "label": "Back of Photograph", 
      "classified_as": [
        {"id": "aat:300190692","type": "Type","label": "Back Part"}
      ], 
      "carries": [
        {
          "id": "https://linked.art/example/text/25", 
          "type": "LinguisticObject", 
          "value": "Photograph of Example Artwork, taken 1932"
        }
      ]
    }
  ]
}

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