To keep placed PDF drawings sharp while reducing photo size, preserve eligible drawings with PDF Passthrough and adjust the PDF export’s raster-image settings. This Mac workflow depends on the drawing remaining suitable for passthrough; effects or incompatible export settings can force rasterization.

This guide covers exporting an Affinity layout containing placed PDF diagrams and separate photographs. It follows the current Affinity desktop Help Center’s controls and documented limitations. Affinity describes Passthrough as providing exact PDF reproduction where possible, while its export controls separately govern rasterization, downsampling, and JPEG compression. Placing content, Export Settings

What allows drawings to stay sharp while photos shrink?

The useful distinction is between vector content and raster content. Affinity’s Downsample images setting applies to raster images, and Allow JPEG compression compresses rasterized design elements. Preserving an eligible PDF drawing through Passthrough provides a route to retaining its original drawing content while applying image compression elsewhere in the layout. This workflow follows the documented division between placement and export controls. Placing content, Export Settings

A PDF filename alone does not establish that its drawing consists of vectors. For this workflow, start with a PDF whose lines and labels already look satisfactory in the original file. Passthrough is documented as reproducing the PDF; it is not a tool for reconstructing sharper drawing detail from an already soft source. Placing content

There is also no documented “compress photographs only” switch in the cited PDF export settings. The controls are described by content type—raster images and rasterized elements—not by whether an object depicts a photograph or a diagram. Consequently, a drawing that becomes rasterized can enter the same image-processing path you intended for the photographs. Export Settings

Place the PDF without losing Passthrough

Use the original PDF as a placed document in your layout. On the Mac desktop, choose File > Place, select the PDF, and click Open. If the Place panel appears for a multipage document, select the required page. Click the layout page to place content at its native size, or drag to define its size and position. Placing content

Select the placed PDF and inspect its context toolbar. Its Passthrough setting should be Passthrough. Affinity says this is the default for exact reproduction; when that is not possible, it selects Interpret. For a multipage PDF, the context toolbar’s Spread control lets you choose the displayed page, although only one PDF page is displayed per placed object. Placing content

Keep these two documented changes in mind:

  • Editing an embedded PDF’s contents converts it to an Affinity document, discards the retained original data, and loses PDF Passthrough.
  • Changing the visibility of layers inside a placed PDF through the context toolbar’s Layers setting automatically changes PDF Passthrough to Interpret.

If the drawing needs either change, a practical approach is to revise its source, produce a replacement PDF, and place that version. Placing content

Both linked and embedded placement are documented. Linking alone is not the sharpness control: preserve the PDF’s eligibility for Passthrough. For linked documents, external changes are reported as Modified in Resource Manager and can be updated there. Placing content

Do not judge the result solely from the Affinity canvas. The application displays a bitmap preview of a placed PDF while you edit. A soft-looking editing preview therefore does not, by itself, establish that the exported drawing has been rasterized. Check the exported PDF as well. Placing content

Set PDF export to compress raster content

Choose File > Export > Export. Select a PDF preset on the left, then inspect the settings on the right, including the Advanced section. Set Area deliberately: use All Pages for separate publication pages, or the appropriate whole-document or artboard option for your document. Export dialog

For an initial export, PDF (digital - high quality) is a useful documented starting point. Affinity’s preset comparison lists Rasterize: Unsupported properties, Raster DPI: 300, downsampling enabled with Above (DPI): 375, JPEG compression enabled, and Quality: 98. These are preset defaults, not a promise that every placed PDF will pass through. Compare PDF export presets

The controls have different jobs:

Control Documented purpose How to use it here
Rasterize Determines how unsupported design elements are handled Start with Unsupported properties, then investigate any rasterization affecting drawings.
Raster DPI Sets resolution for effects rasterized on export Treat this as an effects-resolution setting, rather than a universal drawing-sharpness control.
Downsample images / Above Controls downsampling of raster images according to their DPI Enable when you intend to reduce raster resolution; inspect drawings that contain raster content.
Allow JPEG compression / Quality Compresses rasterized elements and controls their quality Adjust to reduce photo data, checking the visible result after each change.

These descriptions come from Affinity’s Export Settings.

Make one adjustment at a time. For example, keep the high-quality preset’s resolution settings and try lowering Quality from 98 to 85. That is an illustrative comparison, not a universal recommendation. Affinity documents that higher quality can produce significantly larger files; the acceptable setting depends on your photographs and viewing size. Export Settings

For comparison, PDF (digital - small size) uses Raster DPI 72, Above DPI 90, and Quality 85. Switching to it therefore changes several settings at once. Use it as a separate candidate when those lower raster settings suit the document, rather than assuming its only difference is stronger JPEG compression. Compare PDF export presets

Avoid PDF (flatten) for the vector-preservation route: its documented Rasterize setting is Everything. Also avoid treating Rasterize: Nothing as a universal repair. Affinity explicitly states that unsupported elements are omitted when Nothing is selected. A sharp-looking export with missing content does not complete the task. Compare PDF export presets, Export Settings

Check the conditions that force a placed PDF to rasterize

Before settling on compression settings, run Preflight. Select the preflight indicator in the status bar to open its panel, then click Check Now. The panel also offers Live and Export checking. Inspect the active profile’s PDF passthrough checks; the profile determines which issues are reported. Preflight

Affinity documents the following reasons a placed PDF will be rasterized on export:

  • Image adjustments applied to the placed PDF.
  • Effects applied to it.
  • Transparency applied to it.
  • A placed PDF version incompatible with the export version.
  • Object colors incompatible with the export version.
  • An unsupported page box.

It separately reports missing or broken PDFs. These are placement or compatibility problems to resolve before reducing photo quality further. Preflight

Match the remedy to the warning. Remove an unnecessary effect or transparency from the placed drawing. For a version warning, review the PDF export’s Compatibility setting and choose a compatible output type that also meets your delivery requirements. Affinity documents compatibility choices including PDF 1.4 through 1.7, PDF 2.0, and several PDF/X options; it does not document one choice as guaranteeing passthrough for every source PDF. Preflight, Export Settings

Read color messages carefully. Affinity distinguishes an incompatible-color warning that causes rasterization from a message saying a placed PDF contains colors different from the document color space but will still pass through. The wording of the actual message matters. Preflight

Use a controlled comparison to find what damages the drawing

Create two exports from the same unchanged layout. For the reference export, disable Downsample images and Allow JPEG compression. For the compressed candidate, enable the intended image settings. Keep Rasterize, Compatibility, page selection, and other settings identical. This comparison is an editorial diagnostic derived from the documented controls, not an Affinity test result. Export Settings

Open both PDFs in your Mac PDF viewer. Compare the same small labels, diagonal lines, and photo details at matching magnifications, and compare their actual file sizes in Finder. Use this decision sequence:

Observation Next action
Drawing looks poor in both exports Compare the original PDF, then investigate placement, interpretation, and rasterization.
Drawing looks good in the reference but worse in the compressed candidate Isolate downsampling and JPEG compression by changing one at a time.
Drawing stays satisfactory but photos look poor Increase photo quality or use less aggressive downsampling.
Both look satisfactory and the candidate is smaller Retain those settings and inspect the remaining pages.

This comparison helps locate the problem; visual inspection alone is not proof of the PDF’s internal object structure. Combine it with Passthrough status and Preflight findings. Affinity also provides Preview export when complete, which opens the exported PDF in your default viewer. Export Settings

When global compression cannot preserve the drawing

If the drawing contains important raster detail, or must be rasterized to reproduce required effects, the documented PDF controls do not provide a separate photo-only compression rule. A supported alternative is to prepare smaller photo files individually and leave the final PDF’s downsampling and JPEG compression disabled. This gives each photograph its own preparation step while avoiding those two additional export operations across the layout. Export Settings

Open each photograph separately in Affinity and use File > Export > Export to create a JPEG copy. Set its Quality and, if appropriate, Width and Height, preserving the aspect ratio. Keep the original photo. Back in the layout, select the corresponding photograph and use Replace Image on the context toolbar to substitute the prepared copy. Inspect its crop and detail after replacement. JPEG quality and dimensions are documented export controls, and Replace Image is the documented replacement command. Export dialog, Export Settings, Placing content

This alternative gives you direct control over the photo assets, but it does not restore Passthrough or repair an inadequate drawing source. Resolve those issues separately, then export and compare again. The finished result should satisfy three checks together: readable drawing detail, acceptable photographs, and a file size suitable for its intended use.

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