This application is quick to complete and involves three easy steps. When you participate, the platform will load a scanned drawing of an amphora such as the one below. These drawings are typical of how archaeologists traditionally record vessel shapes, with the outside of the vessel shown on one side of the drawing and the interior profile shown on the other side (sometimes also with a further section showing the handle shape).

We are asking for help in digitising these drawings as 2D polygons that can then be used for futher analysis. These polygons also have the advantage of being ready for conversion into a 3D model (you can see examples here).

Once the scanned drawing has been loaded, you will proceed in a series of three quick steps as follows:

• Draw and input the dimensions of the scale bar shown in the image.
• Draw a line to clarify where the left-hand handle breaks away from the body of the amphora.
• Draw a line between the observed handle section.

In step 1, you will be asked to draw a line from on end of the scale-bar shown in the drawing to the other.

• Please only enter two points to create the line, not more!
• Once you have drawn the line, it will appear in green. Then please enter the stated width of the line in the box provided above the drawing.
• Please make sure you input this width in metres (so if the scalebar says 50cm, enter 0.5).

Step 2 is slightly more complicated and asks you to use your judgment in drawing a hypothetical line along the curve of the amphora body that distinguishes it from the left-hand amphora handle. You line will be shown in yellow once you complete the sketch. Around handle joins, you will need to guess how the outline continues. Begin your line below the handle and end it above the handle. NB: Please start your line in the empty space outside the amphora and then start clicking along the amphora body. The last portion of your line should also end outside the amphora. In a sense, you can think of your line as something like a knife that can be used to 'cut' the handles off from the amphora body in a clean, attractive way. For example, your end result should look something like the one below (not the start and end points beyond the amphora body).

In the last step, you will be asked simply to identify both the handle cross-section and the empty hole between the handle and the amphora body (on the left-hand side of the amphora), by drawing a line from one to the other. Please begin by clicking on the cross-section and then click somewhere in the middle of the hole. Your line will be shown in brown once you complete it and should look a bit like the one below. (NB. In the rare situation where your image does not havea cross-section drawn on it, just create a small line that falls completely inside the handle hole)

How to use the application's digitising toolbar:

Photo loaded: This label simply indicates whether or not you are waiting for the scan to be loaded into the application. If it says 'Photo loaded', then you can begin digitising.

Scalebar: This label indicates what part of the amphora you are currently digitising.

Draw: This option is selected by default, at the beginning of a task. Click on 'Draw' whenever you want to start drawing a line or polygon. Once you complete your drawing of a feature, the delineating line will turn from blue to a different colour.

Edit: This option is enabled once there is at least one complete feature drawn. After clicking on 'Edit', choose the line or polygon you wish to edit by clicking once anywhere on it. It will turn blue, and become available for editing such that you will be able to re-position the blue nodes that give the line its shape.

Delete: Use this option if you wish to delete your existing drawing (for the current step only).