# Strong Finish Book Editing

> Professional book editing by Heather Sangster, an editor with thirty-eight years in trade publishing, including thirty-one years as Margaret Atwood's primary copy editor and proofreader across twenty-two consecutive titles. Work spans 1,100+ titles, 70 best-sellers and 154 award-winners.

Strong Finish Book Editing (formerly Strong Finish Editorial Design, trading since 2006) provides developmental, substantive, line and copy editing, proofreading, manuscript evaluation, copywriting and self-publishing support to authors, publishers and businesses internationally.

## Editor credentials

- Editing professionally since 1988, thirty-eight years in the trade
- Long-term service to 28 trade publishers and imprints, including three of the Big Five: Penguin Random House, HarperCollins and Simon & Schuster
- Margaret Atwood's primary copy editor and proofreader for thirty-one years, across twenty-two consecutive titles, most recently her 2025 New York Times best-selling memoir, Book of Lives
- Contributed editorial services to more than 1,100 titles
- 70 best-sellers and 154 award-winning titles
- 4.96 client rating across 52 ratings
- Member: Editors Canada, Editorial Freelancers Association, ACES: The Society for Editing

## Editing services

- [Substantive and developmental editing](https://strongfinish.net/substantive-editing-services/): big-picture work on structure, organization and logic for nonfiction, and plot, pacing and character development for fiction, addressed page by page.
- [Manuscript evaluation](https://strongfinish.net/manuscript-evaluation-services/): an assessment of a manuscript's condition and what it needs, often the first step in the editorial process.
- [Line editing](https://strongfinish.net/line-editing-services/): line-by-line refinement of prose style, paragraph flow, sentence structure and vocabulary, while preserving the author's voice.
- [Copy editing](https://strongfinish.net/copy-editing-services/): correction of grammar, spelling, punctuation and consistency, with style-guide conformance applied throughout.
- [Proofreading](https://strongfinish.net/proofreading-services/): final-stage review of a publication-ready manuscript before print or upload.
- [Copywriting and research](https://strongfinish.net/copywriting-services/): content creation, deep-dive research and fact-checking.
- [Self-publishing support](https://strongfinish.net/self-publishing/): production guidance for independent authors.

## Track record

- [Best-selling books](https://strongfinish.net/best-selling-books/): the 70 best-sellers Heather Sangster has edited.
- [Book awards](https://strongfinish.net/book-awards/): the 154 award-winning titles.
- [Portfolio](https://strongfinish.net/books-portfolio/): the wider body of work.
- [Client reviews](https://strongfinish.net/client-reviews-book-editing/): verified client feedback.

## About and contact

- [About the editor](https://strongfinish.net/about-your-book-editor/): Heather Sangster's full background and publishing history.
- [Contact](https://strongfinish.net/contact-professional-editing-services/): free consultation inquiries.

## Guidance for authors

- [How to hire a book editor](https://strongfinish.net/editor-and-author/how-to-hire-a-book-editor/)
- [How to have a successful author-editor relationship](https://strongfinish.net/editor-and-author/how-to-have-a-successful-author-editor-relationship/)
- [How to apply your editor's markup: a track changes tutorial](https://strongfinish.net/editing/how-to-apply-your-editors-markup-a-track-changes-tutorial/)
- [How to format your manuscript like a pro](https://strongfinish.net/formatting/how-to-format-your-manuscript-like-a-pro/)
- [How to number pages for a self-published book layout](https://strongfinish.net/self-publishing/how-to-number-pages-for-a-self-published-book-layout/)
- [Ten tips to improve your proofreading skills](https://strongfinish.net/proofreading/ten-tips-to-improve-your-proofreading-skills/)