Strong Finish Book Editing Services



Books Strong

First-class book editing services for three decades: manuscript evaluation, substantive editing, line editing, copy editing, proofreading, and production support.



Serving Clients Worldwide

canada, USA, england,
france, switzerland,
netherlands, spain, china


(logos copyright of their publishers)

Featured Title

The Testaments

Heather Sangster of Strong Finish copy edited and proofread Margaret Atwood’s
The Testaments, the internationally best-selling, 2019 Booker Prize–winning sequel to The Handmaid’s Tale.

It’s Heather’s 17th title with the highly esteemed author and recipient of multiple prestigious awards, including the Commonwealth Writers’ Prize, Giller Prize, and the National Book Critics and PEN Center USA Lifetime Achievement Awards. A number of Atwood’s books have been adapted for film, television, and theatre.

“Many thanks are due to … Heather Sangster of Strong Finish, the demon copy editor who picks every nit, including those yet unhatched.”
~ Acknowledgements in The Testaments

“Heather Sangster has been the primary copy editor of my work for the past 25 years and my publications owe a great deal to her services. She is meticulously thorough and thoroughly professional.”
~ Margaret Atwood

Strong Finish
in The Globe and Mail

Making the Right Calls

Specializing in best-sellers, award-winners, and the development of emerging talent, Strong Finish delivers high-calibre professional book editing services, including manuscript evaluation, substantive editing, line editing, copy editing, proofreading, copywriting and research, and production support.

A combination of classic principles, contemporary sensibilities, insider expertise, and just the right touch delivers a signature service with measurably superior results.

Whether you’re an author, publisher, or savvy business who needs book editing services or publishing advice, Strong Finish can surely help.

Book Editing Services

manuscript evaluation

Insightful analysis of your content and technique along with effective suggestions in a detailed report.

substantive editing

A big-picture examination to shape structure,
credibility, voice, and message.

line editing

A thorough line-by-line edit focusing on style, improving flow, tone, and clarity.

copy editing

A rigorous review to correct mechanical issues such as grammar, spelling, and punctuation.


A meticulous final read for accurate and reliable
quality control, resulting in a polished project.

copywriting & research

Persuasive, natural copy that ignites action. A deep dive into fact-checking and supplementary analysis.

Portfolio Sample

Let’s Get You There

Your book—my advice—no strings attached. I’ll provide clarity and peace of mind by showing you next steps and pricing.