Mixam’s Proof Types
Proof Type 1: The Artwork Thumbnails
When you upload your files, they’ll appear in thumbnail form in your Artwork Dashboard. One thumbnail is equivalent to one page if you are ordering bound items like Books and corresponds to one side if you plan to print flat items, like Posters.
Our system will flatten your artwork, meaning it’ll appear in a low resolution. The thumbnails will show you any overlays, binding lines and file issues. Even though the colours will not be completely accurate, you can check your page sequence, content and the positioning of your files. Our system will process your files in CMYK colour mode, not RGB. Please read this guide to learn more about converting RGB files to CMYK.
We also advise removing these guidelines to check you have added sufficient bleed. Click Show guide lines and legend in your Artwork tab, and it will reappear when you click the box again. If you spot an issue with your preview, resupply your files with bleed or contact our team for advice on alternative options.

Our Thumbnails will also show:
- Trim box: these green lines show where we aim to trim the paper.
- Bleed box guideline: these blue guides ensure your artwork goes beyond the edge of the paper to prevent white, unprinted lines from appearing once trimmed to size, providing you supply your artwork files with bleed.
- Gutter box: this pink/purple shaded space indicates what may be lost or partially obscured by the binding in perfect bound books, like Hardcovers.
Warning and error messages may appear throughout the process, so please check and correct them before you confirm your order. If you send your project to print without resolving the issues we flag, we cannot then fix any that might arise. Please note that thumbnails represent a page or side as an image. They indicate how your work could look in print and are NOT an exact replica. But the trim, bleed, and gutter margin will not appear on your finished prints - they’re just guidelines.
Proof Type 2: The Preview
This format is the best way to ensure your pages and artwork are present and appear in the correct order. You can find the Preview button at the top of the Artwork section with an eye symbol. Our system will generate a virtual 3D representation in a flipbook or flat-sided format depicting your artwork without showing the bleed (click here for an example). You can also share your work with others by pressing the Share button at the top of the preview (arrow pointing to the right inside a box).

Proof Type 3: The Downloadable Proof
The Downloadable Proof is the most critical part to check in the proofing process. It’s the closest representation of how your files will appear in print. Please note that on-screen colours can vary between devices and depend on your settings. You can find the Downloadable Proof next to the Preview button at the top of the Artwork section with a document symbol. For most internet browsers, once your artwork is uploaded, here’s how to download this proof:
Click the Proof button > Wait for the checkmark to appear > Click again to open the Proof > Click the Download button (arrow pointing down above a straight line). Or...
Right-click the Proof button and use the Save As option to save your PDF file > Open and check your file on your device with the Overprint Preview instructions further down.
We strongly recommend downloading the proof to your device. This proof will highlight any hidden issues that may not have been apparent in the Preview or Thumbnails. You should view your artwork with a professional PDF reader like Adobe Acrobat. While you cannot edit a PDF file, it will give an impression of how your colours and text could look. If you see differences between these proofs, contact us for advice.
Proof Type 4: High-Value Orders - Professional Proofs
Consider the Professional proof as printer-ready. We will email you to let you know when your Proof is ready for inspection. While Professional Proofs aren’t colour accurate, text and image errors on processed files will become apparent - so you can adjust any errors before your files go to the final print run.
Professional Proofs are free and necessary for orders over £5,700. Requests for extra proofs can be subject to further costs. Your prints will only enter production once you approve Professional Proof. If you reject your proof, you will need to contact us and explain why you are dissatisfied with it so we can help you make corrections. Please note that rejecting your proof can also affect shipping and delivery dates.
Checking your Proofs
We recommend taking the time to complete the following when proofing your files:
- Manual check – Review all issues our system flags and manually check every page. Our system will highlight most technical printing issues, but we combine our technology with experienced print experts who will quality-check your work before and after print.
- Images – We will warn you if your artwork is under 100dpi. Missing this step can delay your print work going into production, so please double-check your files before proceeding.
- Bleed – Click on each thumbnail to ensure the content is within the trim lines. You can also check that critical information is not within the quiet areas (safety margin) or in the gutter margin (if your item will be perfect bound).
- Text – If you’re alerted to a font issue, make sure they are embedded, as we won’t be able to print your work. If this issue occurs, you must embed the font on your original file and resupply your files. Also, keep an eye out for missing text and odd text characters. And always proofread and spell-check your print files before uploading. You could even use writing assistant tools like Grammarly to check any text you want to include in your final prints.
If you, or a Mixam print expert, make any changes to your artwork files or print specifications, be sure to review the Thumbnails, Preview and Downloadable Proof again. You can edit your files as much as you like - so give yourself plenty of time to make changes until you are satisfied with the outcome.
You are responsible for preparing every element of your print files. We work from the understanding that when you confirm your order, you’ve checked your files, and you are happy for us to print them as they are. But our print experts can always help you resolve issues before sending your work to print. To avoid common print issues, follow our print checklist.
Friendly reminder: Please ensure your content is legal, copyright-free and doesn’t breach our T&Cs.

View Proofs with Overprint Preview
We recommend turning on the Overprint Preview in Adobe Acrobat Reader when viewing your Downloadable Proof. Overprint Preview will give you an accurate representation of your final prints on-screen, so please check the downloaded version thoroughly before confirming your order.
This function will also prevent colour loss, and you can see any transparencies mixing with spot colours. We recommend setting this as a default so you can see your work in high definition. To turn on the Overprint Preview, complete the following steps:
On a PC: Go to Edit > Preferences > Select Page Display > Under Page Content and Information, the Use Overprint Preview dropdown menu, confirm or change to be set to Always.
On a Mac: Go to Acrobat > Preferences > Page Display > Under Page Content and Information, the Use Overprint Preview dropdown menu, confirm or change to Always.
Colour Matching
You should upload your print files in CMYK colour mode. Our system will automatically convert any RGB files to CMYK. However, this can cause colour variations, so design your artwork using CMYK.
We cannot guarantee that the colours on your screen will match the colours on your final prints. If colours are critical, contact us, our print experts will do their best to help you achieve colour-accurate work where possible.


Delivery Dates
If a print expert flags any issues with your print order, it can delay the printing process until resolved. But our print experts will work with you to fix these issues. To avoid delays, please check your work carefully before uploading your files in the first place.
