Testing EPILOG and GCC for Banding Issue - Acrylic

1. Drawing

Draw a solid black filled rectangle in CorelDraw.

2. Printing (i.e., sending files)

Choose raster for fill engraving

Several fill patterns are dithered dot matrix; there's no continuous line pattern.

3. Preview

At 600 DPI, the small image preview shows continuous black fill (within the red box).

When zoomed in sufficiently, it becomes evident that it's actually a dot matrix pattern.

At 1000 DPI, the dot matrix pattern remains visible even when zoomed in.

At 75 DPI, the dot matrix pattern becomes more pronounced, and it's noticeable even in the small image preview.

4. Engraving

Inspecting each engraving outcome under a microscope. Upon examining the magnified engraving results, it's apparent that Epilog's horizontal movement isn't entirely straight, and the spacing between lines isn't consistent either. This is particularly noticeable in cases (3), (4), and (5).

(1) : DPI 75, Speed 100%, Power 20%

(After engraving, the original white dot matrix turned black for better visibility, using a whiteboard marker.)

(2) : DPI 75, Speed 50%, Power 20%

(3) : DPI 150, Speed 50%, Power 20% — Due to the dot matrix pattern, increasing the DPI from 75 to 150 results in twice the number of dots both vertically and horizontally, with horizontal dots now connected in (2).

(4) : DPI 200, Speed 50%, Power 20%

(5) : DPI 75, Speed 50%, Power 10%

5. Bidirectional Fill

(1): DPI 300, Speed 20%, Power 20%

Vertical stripes are noticeable, though not very pronounced.

(2) : DPI 600, Speed 20%, Power 20%

The effect appears more uniform.

(3) : DPI 600, Speed 20%, Power 10%

(4) : DPI 600, Speed 20%, Power 100%

The engraving results from Epilog show a very favorable outcome, with no visible stripes.

The overall fill engraving effect from GCC is also quite satisfactory, and there are no vertical stripes.

(Note: Due to incorrect software settings, the parameters indicated in the image are not the actual engraving parameters; they are only for observation purposes.)

For GCC, the minimum DPI is 250. At lower DPI levels, it's noticeable that even its vector fill isn't a continuous illumination but rather a regular dot matrix.

Upon magnified observation under a microscope, it becomes apparent that this dot matrix isn't perfectly uniform either. While most areas exhibit two spots aligning precisely, there are instances of slight separation in certain regions. However, this doesn't significantly affect the overall engraving effect.