How to Set Up and Use Multi-Part PDF Separation for More Accurate Previews and Outputs

What’s Changed

Multi-part PDF products have been improved to give you more control over how files are handled throughout the workflow.

Previously, all uploaded PDFs (such as cover and body files) were automatically merged into a single document during preview and output. This often caused issues, especially when files had different sizes or orientations.

Now, each part can be handled independently. This means each uploaded PDF remains separate during preview and output, different preview styles can be applied per part, and files are no longer forced into a single combined preview. The result is a more accurate representation of the final product and a cleaner handoff into production.

What It Was Like Before

Before this update, all files in a multi-part product were combined into a single PDF during preview and output.

This created several challenges. Mixed page sizes (for example, landscape covers and portrait inner pages) often appeared distorted in preview. It also made it harder for production teams to work with individual files, as they needed to manually split combined PDFs downstream.

Overall, the workflow worked, but it wasn’t ideal for more complex or production-heavy use cases.

Pre-Requisites

Before setting this up, make sure:

• You are working with a MultiPart product
• Your product uses file upload parts (e.g. cover, body, back)
• You are primarily working with PDF files
• Your product configuration supports part-based setup

It’s also recommended that preview confirmation is enabled, as some preview behaviours depend on it.

How to Set It Up

Setting this up involves configuring your product so each uploaded file is treated as a separate part, rather than being combined into a single document.

1. Create or Edit a MultiPart Product

Start by navigating to your product in the admin:

• Go to Admin → Products
• Create a new product or edit an existing one
• Ensure the product supports MultiPart uploads

Example

You might have a booklet product with:

• A cover
• Inner pages
• A back cover

Each of these should be treated as separate parts instead of one combined file.

2. Define Each File as a Separate Part

In your product configuration, define each section as its own part.

Example:

 

<Parts>
<PartConfiguration type="userupload" name="cover" />
<PartConfiguration type="userupload" name="body" />
<PartConfiguration type="userupload" name="back" />
</Parts>

 

 

Then map these to upload fields:

 

<InputItems>
<InputItem type="part">
<ItemInfo>
<InternalName>cover</InternalName>
<UIName>Cover (Upload PDF)</UIName>
</ItemInfo>
</InputItem>

<InputItem type="part">
<ItemInfo>
<InternalName>body</InternalName>
<UIName>Body Pages</UIName>
</ItemInfo>
</InputItem>

<InputItem type="part">
<ItemInfo>
<InternalName>back</InternalName>
<UIName>Back Cover</UIName>
</ItemInfo>
</InputItem>
</InputItems>

 

 

 

This ensures each uploaded file is handled independently.

3. Set the Correct Part Type

Different part types allow you to control how files are handled.

• userupload → for files uploaded by the user
• asset → for predefined or system-managed files

Example:

 

<Parts>
<PartConfiguration type="userupload" name="cover" />
<PartConfiguration type="asset" name="intro_pages" mode="asset" />
<PartConfiguration type="userupload" name="body" />
<PartConfiguration type="userupload" name="back" />
</Parts>

 

In this setup:

• The cover, body, and back are uploaded by the user
• The intro pages are treated as a separate asset

This separation allows previews and outputs to remain structured and accurate.

4. Enable Individual Preview Where Needed

You can control how each part appears in the preview.

Example:

 

<Parts>
<PartConfiguration type="userupload" name="cover" individualPreview="true" />
<PartConfiguration type="userupload" name="body" individualPreview="false" />
<PartConfiguration type="userupload" name="back" individualPreview="true" />
</Parts>

 

This results in:

• Cover → displayed as a standalone preview
• Body → displayed as a booklet-style preview
• Back → displayed separately

This is particularly useful when working with different page sizes or orientations.

5. Ensure Preview Settings Are Enabled

In your configuration, make sure preview is properly enabled:

 

<Configuration previewModeType="normal" confirmPreview="true">

 

 

The key setting here is:

• confirmPreview="true"

If this is disabled, some preview functionality may not work correctly.

6. Restrict File Types to PDF (Recommended)

To ensure consistent behaviour, limit uploads to PDF files:

 

<AllowedMimeTypes>application/pdf</AllowedMimeTypes>

 

This avoids unexpected behaviour with unsupported formats.

7. Apply PDF Profiles Per Part (Optional)

If you are using PDF validation or fix profiles, you can apply them per part:

 

<PartConfiguration
name="body"
requiredCheckProfile="Print Check"
optionalFixProfile="Print Fix"
/>

 

This allows different sections of the document to follow different production rules.

Complete Example Configuration

Below is a full example of a MultiPart product configuration showing how different parts (cover, body, intro/outro, back) can be structured, previewed, and processed independently.

This example includes:

• Mixed user uploads and asset parts
• Different preview behaviours per part
• PDF profile configuration
• Upload field mappings

8. Test the Setup in MegaEdit

Once configured, open the product in MegaEdit and upload files.

For example:

• A landscape cover
• A portrait body

Check that:

• Each part previews correctly
• Covers appear separately
• Inner pages display correctly
• No distortion occurs

9. Validate Output and Downloads

Place a test order and confirm:

• Files are not merged into a single PDF
• Each part is available separately
• Outputs match the original structure

This is especially important if you are using integrations or automated workflows.

Tips to Improve User Experience

To get the best results, structure your product clearly from the start.

Use clear naming for upload fields so users understand what to upload. Keep file types consistent, and align preview styles with the type of content being uploaded.

If your product includes different formats (such as landscape covers and portrait inner pages), separating them into parts will significantly improve preview accuracy.

Troubleshooting

If something doesn’t behave as expected, start with a few key checks.

If previews are not working correctly, confirm that preview settings are enabled and that individual preview is configured correctly for each part.

If files still appear combined, review your part configuration and ensure each file is defined separately.

If previews look distorted, this is usually due to mixed page sizes being forced into the wrong preview mode - check your preview settings.

If outputs are not separated, verify that the correct part types are being used and that uploads are mapped correctly.

Summary

This update gives you much greater control over how multi-part PDFs are handled across the entire workflow.

By keeping files separate, improving preview accuracy, and aligning outputs more closely with production needs, it removes a lot of friction for both users and print teams.

For any product involving multiple files - especially those with different formats or finishing requirements - this results in a more reliable and professional workflow.