Drawing preparation

Identify the drawing pair

Choose an original and revised drawing for the same part, assembly, or sheet. Confirm the drawing number, revision labels, and title-block information. Retain the source drawings so reviewers can verify any detected change.

Check units and scale

Use consistent drawing units and confirm that the same physical feature has the expected size in both revisions. Inspect a known dimension before interpreting the overlay. A scale difference can affect much of the drawing and obscure smaller edits.

Check coordinates and orientation

Confirm that the drawings use consistent origins and orientation. A translated or rotated view can create widespread differences even when its geometry has not changed. Investigate positioning differences before treating the overlay as an engineering change list.

Prepare DXF inputs

Use DXF when entity geometry is available. Include the layers needed for the review, particularly geometry, dimensions, notes, and title-block details. Confirm that exported entities appear as expected in the source drawing and in the comparison.

Prepare vector PDF inputs

Use a vector export with legible dimensions and notes. Check page size, drawing scale, orientation, and sheet order. Text converted to outlines may retain its appearance while losing the information needed for word-level interpretation.

Scanned and image-only PDFs are outside the current vector comparison workflow. Check supported drawings and limits before submitting them.

Prepare multi-sheet sets

Match sheets by drawing identity rather than page position alone. Review any sheet insertion, deletion, or reordering before relying on page-by-page results. Confirm the sheet and drawing zone when discussing a change.

Continue with getting started or the comparison sheets.