When viewing a PDF or image in CoLab, you can leave pieces of General Feedback, or you can use CoLab's markup tools located at the top left of your screen to add markups directly to the file. You can then save your markups as Feedback items and assign them to other CoLab users.

Placing markup on a PDF or image will automatically generate a feedback item, which can then be assigned to another user and further discussed via a discussion thread.

Here’s an overview of each 2D markup tool:

You can create feedback that applies to the file in general which is not specific to a certain aspect of the file.

You can select single markup by clicking on an object or click and drag on the canvas to select multiple objects. Once an object or multiple objects are selected you can click and drag those objects around the canvas. If a single object is selected, you can click on the anchors located on the corner of the object.

Allows you to make pen-like markups on the PDF or image. Click on the ‘Pen’ button to expand the toolbar with stroke colour and stroke width options to change the colour of the stroke or its width.

Allows you to make highlights on the PDF or image. Click on the ‘Highlight’ button to expand the toolbar with the stroke colour button to change the colour of the stroke.

Allow you to select a desired shape that is used to highlight an area and leave feedback on it. Click on the Markup Shapes button to expand the toolbar with options to change the fill colour, shape colour and stroke width.

Allows you to draw lines on the PDF or image. Click on the Line button and use the Stroke Color and Stroke Width buttons to modify the line.

Allows you to add GD&T markup on or around the PDF or image. Click on the 'GD&T' button and select fill colour, stroke colour, stroke width, and font size to modify the markup. You can also select whether or not to show an arrow pointing to the exact location on the PDF or image. Double click on the 'GD&T' button to make it the dominant markup tool in use.

Allows you to draw arrows on the PDF or image. Click on the Arrow button and use the Stroke Color and Stroke Width buttons to modify the shape.

Creates an arrow, associated text box and feedback window. Click on the Callout button to expand the toolbar with options to change the shape fill, line colour, text colour, shape line width and font size. Text entered in the text box will be auto-populated in the feedback title.

Allows you to place text boxes on the PDF or image. Click on the Text button and use the toolbar options to change the text colour or size. Text entered in the text box will be auto-populated in the feedback title.

Allow you to undo or redo any of the activities from this toolbar.

Allows you to delete any activities from this toolbar. WARNING: deleted activities cannot be recovered.