From Artwork Tracing to Verified Machine-Ready Cutting Files
Waterjet mosaic production begins long before the cutting head moves. The accuracy of the finished inlay depends on how the original artwork is converted into closed CAD geometry, divided into individual parts, assigned to the correct materials, compensated for the cutting kerf and translated into a machine-readable program.
This guide focuses specifically on waterjet mosaic file preparation and programming. Its scope ends when the cutting file has been verified through simulation and a representative test cut. Material bonding, pressing, surface finishing and site installation belong to the later production stages.
A waterjet mosaic file is prepared by converting the source artwork into accurate vector geometry, confirming the finished dimensions, dividing the design into manufacturable parts, grouping those parts by material, nesting them on the available slabs, applying kerf and joint compensation, assigning piercing and lead-in positions, arranging the cutting sequence and exporting a file compatible with the machine controller.
Before production begins, the programmer should run a path simulation and complete a test cut using the actual material, thickness, nozzle condition and cutting setup. The verified result—not a general software default—should determine the final compensation value.
A mosaic drawing may look correct on a screen but still produce parts that do not fit together after cutting. CAD geometry represents the intended shape; it does not automatically account for the material removed by the cutting stream, the required assembly joint, nozzle wear, edge taper or the behavior of brittle stone and ceramic.
For decorative inlays, a small error can repeat across many neighboring pieces. If each part is slightly oversized, the overall pattern may expand and become difficult to assemble. If the parts are too small, the joints become visually inconsistent. Incorrect material allocation can also interrupt the intended color, grain or veining sequence.
Reliable file preparation must therefore control three connected results:
The dimensions of each individual part
The fit between adjacent parts
The overall dimensions of the assembled design
The purpose of programming is not simply to reproduce the drawing. It is to translate the design into parts that can be cut, identified and assembled under actual production conditions.
The programmer should not begin toolpath preparation from an image alone. The following project information should first be confirmed.
Record the required overall width, height or diameter of the completed mosaic. The drawing scale must be checked against at least one known dimension rather than estimated from the image resolution.
For divided floor medallions or wall panels, confirm the dimensions of each installation section and the location of the dividing lines.
The source may be a JPG, PNG, PDF, AI, SVG, DWG or DXF file. A raster image can be used as a visual reference, but its pixels are not machine-ready cutting paths. Low-resolution images, perspective photographs and compressed graphics require careful reconstruction.
Vector files may save drafting time, but they still need to be inspected for open contours, duplicated lines, overlapping curves and incorrect units.
Each color or visual region should be connected to a specific material. The material schedule should include:
Material name or identification code
Stone, ceramic, porcelain or other material type
Slab or tile dimensions
Material thickness
Surface finish
Grain or veining direction
Available quantity
Visible defects or restricted areas
This information affects part allocation, orientation, nesting and the amount of usable stock.
Confirm whether the design requires a visible decorative joint, a narrow adhesive joint or a closely fitted inlay. Do not assume that the target joint is always zero.
The acceptable joint depends on the material, edge condition, assembly method, adhesive system, installation environment and visual standard. The required value should be supplied or approved for the specific project.
Before exporting files, confirm:
Controller or CAM software
Accepted file format
Drawing units
Coordinate origin
Table orientation
Cutting-head configuration
Layer or color rules
Maximum working area
Whether the controller applies compensation automatically
This prevents a correctly drawn design from being imported at the wrong scale or with missing path information.
Begin by checking whether the source is dimensionally reliable.
A scanned image, photograph or downloaded graphic may contain distortion. Horizontal and vertical dimensions may not remain proportional, and circular shapes may become slightly elliptical. The programmer should therefore establish the finished boundary first and scale the artwork using confirmed dimensions.
Check the following before tracing:
Is the image viewed straight on?
Does it contain perspective distortion?
Is the design symmetrical?
Are border widths consistent?
Are repeated elements genuinely identical?
Are any areas unclear or incomplete?
Does the artwork include shadows or decorative effects that should not become cut lines?
If symmetry is part of the design, construct one accurate section and reproduce it geometrically where possible. This usually creates cleaner and more consistent paths than tracing every repeated feature independently.
Use lines, arcs, circles, polylines, splines and other controlled CAD entities to reconstruct the intended boundaries. Automatic image tracing can provide a starting point, but it often produces excessive control points, uneven curves and small unwanted contours.
Machine-ready geometry should be simple enough to process reliably and accurate enough to preserve the design.
Too many nodes can cause uneven machine motion, particularly along smooth curves. Replace irregular short segments with cleaner arcs or controlled splines when this does not change the design.
Each part boundary must form a valid closed contour. Small gaps may prevent the CAM software from recognizing the shape as a complete part.
Use the CAD inspection tools to detect:
Open endpoints
Unjoined segments
Self-intersecting curves
Overlapping entities
Duplicate lines
Very short isolated segments
Two adjacent parts may share the same visible boundary in the artwork. If both boundaries are copied without checking, the software may generate duplicate paths along the same location.
Repeated cutting can enlarge the joint, damage a narrow feature or waste production time. Every final toolpath should have a clear purpose.
Not every attractive visual detail can be converted directly into a durable cut part. The design should be reviewed according to the actual material and cutting setup.
Pay particular attention to:
Extremely narrow tips
Long thin projections
Sharp internal corners
Small isolated inserts
Short curves with sudden direction changes
Small holes
Narrow spaces between neighboring contours
Parts that have little support during cutting
Details likely to break during handling
An internal corner cannot be sharper than the effective cutting stream and path strategy allow. If the original artwork contains an impossible point, the programmer must introduce a suitable radius or modify the adjoining geometry with design approval.
Fragile details should be simplified only as much as necessary. The goal is to preserve the visual character while making each part practical to cut, sort and handle.
Large medallions, lobby floors and wall features may exceed the available slab size, machine working area or practical handling dimensions. These designs must be divided into controlled sections.
Division lines should be planned rather than placed wherever space is available.
Suitable locations may include:
Existing pattern borders
Natural changes in color
Straight architectural lines
Low-visibility regions
Boundaries between repeated design units
Avoid dividing through important focal points, narrow decorative elements or areas where misalignment would be obvious.
Each section should include:
Section identification
Finished dimensions
Orientation mark
Adjacent-section reference
Installation sequence
Registration or alignment information
The complete design should be checked again after division to confirm that no geometry has been lost, duplicated or shifted.
The complete pattern must next be separated into individual manufacturable pieces. Each piece should receive a unique identification code linked to the assembly drawing.
A useful numbering structure can include:
Project code
Section number
Material or color code
Individual part number
Quantity or mirrored-part designation
For example, a code such as A-M2-014 may identify section A, material group M2 and part 014. The exact format is less important than using it consistently.
Numbering helps the production team:
Match parts to the correct material
Identify mirrored or repeated pieces
Detect missing components
Maintain assembly order
Replace a damaged part without recreating the full project
Separate similar-looking shapes
The identification method must not introduce unwanted cuts into the finished face. Part labels may be maintained in the production drawing, printed layout, removable marking system or another process appropriate for the material.
After separation, assign each part to the specified stone, ceramic or porcelain group.
This stage was described as “taking the block” in the old article, but the more accurate production meaning is part extraction and material allocation.
For natural stone and directional surfaces, rotation changes the final appearance. A nesting arrangement that saves material may still be unacceptable if adjacent pieces show inconsistent veining.
Use direction arrows or locked orientations for parts whose visual direction matters.
If the actual slab contains cracks, filled areas, color variation or damaged corners, mark those restricted regions before nesting. High-value visible parts should not be placed over an unacceptable defect simply to increase material utilization.
Do not combine different colors or thicknesses in one machine file unless the workflow clearly supports it. Separate files reduce the risk of loading the wrong slab or applying unsuitable cutting conditions.
Nesting arranges the parts on each slab or tile while balancing material utilization, cutting stability and appearance.
Effective nesting considers more than how many shapes can fit into the available area. It should also consider:
Material boundaries
Grain and veining direction
Defect zones
Minimum edge distance
Piercing locations
Distance between neighboring parts
Cutting sequence
Small-part stability
Space for safe removal
Recut or replacement requirements
Nesting parts too tightly can create several problems. A pierce point may damage a neighboring part, narrow waste strips may move during cutting, and the remaining material may lose support before later contours are completed.
Material yield should therefore be optimized within a safe manufacturing layout. Nesting can reduce scrap and improve the usable yield of each slab, but the layout must still protect the parts and the cutting sequence.
The cutting stream removes a narrow width of material known as the kerf. If the toolpath follows the nominal geometry without suitable compensation, the finished part dimensions will differ from the drawing.
Kerf compensation shifts the programmed path relative to the nominal contour. The direction depends on which side of the line contains the finished part.
For an external profile, the toolpath normally moves outward from the nominal finished boundary so the cutting stream does not remove material from the required part size.
For an internal hole or opening, the toolpath normally moves inward into the waste region so the opening does not become larger than intended.
Mosaic programming also has to consider the intended space between neighboring pieces. Kerf compensation and joint allowance are related but are not the same value.
Kerf compensation addresses material removed by the cutting stream. Joint allowance addresses the required space between assembled pieces. Both must be considered in relation to the actual cut result.
For two neighboring parts, a simplified design check can be expressed as:
Required change per mating edge = one-half of the intended total joint adjustment
This is only a geometry principle, not a universal machine setting. The final offset must be confirmed by test cutting because actual results can change with:
Nozzle and mixing-tube condition
Abrasive flow
Material type
Material thickness
Cutting speed
Pressure stability
Standoff distance
Edge taper
Controller compensation method
Do not copy a compensation value from a different material or previous project without verification. For a more detailed explanation, refer to Yongtao’s waterjet kerf compensation guide.
Piercing should be located in waste material whenever the geometry allows. Starting directly on a visible finished edge can leave a local mark, chip or enlarged entry area.
A lead-in moves the stabilized cutting stream from the pierce point to the finished contour. A lead-out controls how the stream leaves the completed profile.
For mosaic parts:
Keep piercing away from narrow tips
Avoid piercing inside fragile small pieces when possible
Place entry marks in waste regions
Prevent one lead-in from crossing another part
Use a smooth approach to visible curves
Check whether the lead-out enlarges the closing point
Use an appropriate piercing method for brittle materials
Small internal features may not provide enough waste area for a conventional lead-in. These features require a specific test and path strategy rather than an automatically generated default.
For additional path-planning guidance, review how lead-in and lead-out paths affect waterjet cut quality.
The program should not cut parts only in the order in which the software finds them. Sequence affects material support, head travel, part movement and production organization.
A practical sequence generally considers:
Internal contours before external profiles
Fragile features before surrounding support is removed
Small parts while the parent material remains stable
Reduced travel between distant cutting regions
Completion of one material group or section in a controlled order
Delayed release of parts that could move or tilt
Safe head movement around clamps and fixtures
The exact order depends on the material, nesting layout and holding method. The shortest possible head travel is not always the safest cutting sequence.
Connecting compatible contours into a continuous cutting strategy can reduce repeated start-stop cycles and non-cutting movement. However, continuous paths should not be applied automatically to every group of parts.
A connected path is useful only when it:
Preserves the required part dimensions
Does not cross finished surfaces
Maintains safe piercing and exit locations
Does not release fragile parts too early
Keeps the sequence understandable
Produces an acceptable visible edge
The old article described this simply as “connecting parts in series.” In practice, it is a CAM decision involving path continuity, part stability and cutting order.
If a continuous path creates an uncontrolled bridge, double cut or visible witness mark, separate paths are preferable.
Once the geometry and toolpaths have been checked, export each material plate or production section in the format accepted by the machine software.
Common CAD/CAM exchanges may include DXF, DWG or another controller-compatible format, but the correct format depends on the installed software and control system.
Before export, confirm:
Drawing units are correct
Scale is 1:1
The origin is defined
Part orientation is correct
Required layers are retained
Construction lines are removed or disabled
Text and dimensions are not interpreted as cutting paths
Every contour is complete
Toolpath direction is correct
Compensation has not been applied twice
Separate material files have clear names
The current revision is identifiable
A clear filename may include the project, section, material, revision and date. Avoid generic names such as “final,” “new final” or “plate 1” when several revisions are in circulation.
CAM simulation or dry-path review should be completed before pressure and abrasive cutting begins.
The programmer and operator should check:
Total cutting area
Coordinate origin
Travel limits
Clamp and fixture clearance
Piercing positions
Lead-in and lead-out directions
Cutting sequence
Duplicate paths
Unexpected rapid movements
Uncut contours
Open geometry
Small-part release
Estimated production order
Simulation verifies the program logic, but it cannot fully predict how a specific stone or ceramic material will behave. Physical validation is still required.
The test sample should use the same or a representative material, thickness, cutting-head condition and planned cutting settings.
Do not test only a simple square if the project contains narrow curves, internal corners and closely fitting multi-part joints. The sample should reproduce the critical geometry.
Inspect:
Outside dimensions
Internal dimensions
Actual kerf
Mating-part fit
Joint consistency
Upper-edge chipping
Bottom-edge condition
Taper
Corner quality
Entry and exit marks
Fragile-feature strength
Surface condition
Record the measured result and revise the offset, cutting path or geometry where necessary. After correction, save the verified file as a controlled production revision so an earlier unverified program is not used accidentally.
This usually indicates that a small joint or compensation error is accumulating across multiple adjacent parts. Check the full assembly dimensions rather than measuring only one component.
Possible causes include inconsistent compensation direction, worn cutting-head components, changing cutting speed, taper, incorrectly scaled parts or mixed material thicknesses.
The vector geometry may contain too many short segments, or the file export may have converted smooth curves into low-resolution polylines. Rebuild or export the geometry using suitable curve settings.
Check for open paths, unsupported entities, hidden layers, incorrect file versions or geometry outside the machine working coordinates.
Inspect the source drawing for duplicate entities, overlapping part boundaries or a toolpath generated on both the original and compensated geometry.
Review the nesting distance, support condition, cutting sequence, remaining material bridges and part-retention method. The file should not release unstable pieces before nearby operations are complete.
Verify the actual kerf, compensation direction, intended assembly allowance, nozzle condition and whether the CAM system has already applied an offset.
Check for excessive offset, duplicate cutting, incorrect lead-out placement, nozzle wear, high taper or a test value copied from a different material.
Before a file is released to production, confirm:
The finished size matches the approved drawing
The file uses the correct units and scale
All required contours are closed
Duplicate and overlapping entities have been removed
Each part has a unique reference number
Parts are assigned to the correct material group
Grain and veining direction are marked where required
Oversized designs are divided into controlled sections
Fragile details have been reviewed
Nesting respects material edges and defect areas
Kerf compensation uses the correct direction
Joint allowance is based on the approved assembly requirement
Piercing points are positioned away from critical edges
Lead-ins and lead-outs do not damage adjacent parts
The cutting sequence maintains support
No clamps or fixtures are inside the programmed path
Simulation has been completed
A representative test cut has been inspected
The approved revision is clearly identified
Waterjet mosaic file preparation is one stage of a broader production process. It converts an approved visual design into controlled cutting instructions and provides identification information for later sorting and assembly.
The workflow described here should be completed before batch cutting. Subsequent operations—including cleaning, trial assembly, bonding, pressing, surface correction, final inspection and packaging—should follow a separate production plan.
Workshops that need equipment configured for decorative ceramic, porcelain and stone cutting can review Yongtao’s tile-focused waterjet solutions after confirming their material size, thickness, pattern complexity and production requirements.
Normally, no. A JPG is a raster image composed of pixels rather than controlled cutting geometry. It should first be scaled, traced and rebuilt as clean vector contours. The resulting geometry must then be checked and converted into toolpaths accepted by the machine software.
DXF and DWG are commonly used for transferring two-dimensional geometry, but the correct format depends on the CAM software and controller. The programmer should confirm units, supported entities, layer rules and whether curves are retained correctly after import.
A multi-color mosaic is normally cut from several slabs or tiles. Separating parts by material prevents color allocation errors and allows each plate to be nested, named, cut and tracked independently.
No. Kerf compensation corrects for the width of material removed by the cutting stream. Joint allowance defines the intended space between assembled pieces. Both influence fit, but they serve different purposes and should be verified together through a test cut.
No. Actual kerf and edge behavior can change with material type, thickness, cutting speed, abrasive flow, nozzle condition, pressure stability and standoff distance. A value verified for one tile or stone should not automatically be used for another.
Possible causes include poor-quality source artwork, excessive CAD nodes, short disconnected segments, unsuitable spline conversion or low-resolution file export. Rebuilding the curve with controlled geometry usually produces a cleaner machine path.
In many layouts, cutting internal contours first helps keep the part supported by the surrounding material. However, the final sequence should also consider fragile features, material movement, nesting and the selected holding method.
CAD verifies nominal geometry, but it does not confirm actual kerf, taper, chipping, nozzle wear, material behavior or joint fit. A representative test cut connects the digital design to the real production result.
Divide them along existing borders, color changes, architectural lines or other low-visibility locations. Avoid cutting through focal details or narrow decorative features. Each section should have an identification code, orientation mark and adjoining-section reference.
Confirm the scale, units, origin, closed contours, part numbers, material allocation, nesting, compensation direction, piercing positions, cutting sequence, controller compatibility and revision number. Complete a simulation and representative test cut before batch production.
This guide was reviewed from the perspective of waterjet mosaic drawing preparation, CAD/CAM path planning, material allocation, kerf control and first-cut verification. Final geometry, compensation and process settings should always be confirmed using the actual project drawing, material, thickness, cutting-head condition, controller and assembly requirement.
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0086-18665475362 
[email protected]
Road 3, Wuzhuang Xiaofengtian Ind. Zone, Luocun Town, Nanhai Dist., Foshan, Guangdong, China 
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