White Outline Around a Shape comes with tiny black rim around it

[Erwins_Cat]

Hello,

I came across an issue concerning the outline effect when applying a white outline (on a white or transparent background). When a white outline is set, then the white outline also comes with a tiny, but noticeable, black edge when exported to PDF and viewed with Adobe Acrobat (all zoom levels) or Foxit Reader (vanishes when zoomed in over approx 1000%). The same issue is apparently not present when exporting in other formats, however, the shapes with outlines are getting rasterized, which is also not welcome.

Any idea how to add a white outline to shapes/without causing a tiny black rim to appear in PDF? I'd like to keep a vectorized format if possible of the shapes.t when choosing a black outline on white background. It displays a proper gradient from black to white.

[GarryP]

My first guess is that the image layer is not aligned to the pixels in the document (X and/or Y values are not integer pixel values).
First, go into Preferences / User Interface and change the “Decimal Places for Unit Types” for Pixels to be larger than 3.
Then go to Document Setup and change the “Document Units” to Pixels.
(You can undo the two steps above when you’re done.)
Then check to see if the values for X & Y of the image layer - in the Transform Panel - are integers and, if not, make them integers and see what happens when you export.

[Erwins_Cat]

I tried out your method. In detail, changed the decimal places to a higher value (the highest is 6), changed the document units to pixels and adjusted the curves in the transform panel (some were now 299,998 pixels wide and changed them to integer numbers, e.g. 300), and also restarted affinity.

The issue persists and can be recreated: New document, draw any Bézier curve (probably any shape works, too), add white outline, export as PDF. The outlined curved gets rasterized in that process and the pixelated curve has some black rim at various zoom levels. Apparently the rasterization of "unsupported properties" (fx are all unsupported, right?) plus oddities in PDF viewer messes things up. I guess I have to use another method to add a white outline to shapes. I think creating a copy of a colored curve, coloring it white, add larger line width and placing it behind the colored curve should be the same as outlining curves.

 

[GarryP]

Adding an Outline Effect will always rasterise the layer it is applied to. Maybe someone else will have a better ‘fix’ (I was hoping it would be the usual easy ‘fix’).
However, depending on how your original curves are drawn – if they are curves rather than rasters – then you can – in Designer only (don’t know which Affinity application(s) you have) – add extra strokes to achieve an outline using the Appearance Panel. Vectors – when exported as vectors – should not have any of the problems you have shown.

[Erwins_Cat]

Adding another stroke in the appearance panel is much more elegant than creating a copy of a vectorized curve and solved the issue with the black rim. Thank you 😊

[GarryP]

You're welcome.