How to watermark a PDF without ruining the page
A watermark has to be visible enough to mean something and faint enough to read through. Opacity, placement and size decide which, and most defaults get it wrong.
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Document work,
explained properly.
Practical writing about PDF, image and document work — what is actually inside the file, which settings change the outcome, and how to get it right the first time. Every guide is written here, not reprinted.
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How to convert HEIC to JPG, and why your iPhone uses it
HEIC halves the file size at the same quality, then refuses to open anywhere. Here is how to convert it, and how to stop your phone producing it.
CSV to JSON: the five things that go wrong
Splitting on commas works until a field contains one. Here is what actually breaks in CSV conversion, and how to get types, quoting and encoding right.
How to remove an image background cleanly
Automatic background removal is excellent on some subjects and hopeless on others. Knowing which is which saves you from fighting a tool that cannot win.
How to sign a PDF electronically, and have it count
A drawn signature and a digital signature are not the same thing legally or technically. Here is which one you need and how to apply it.
How to password protect a PDF, and what protection cannot do
PDF has two kinds of password and only one of them actually stops anyone. Here is the difference, and where the protection quietly ends.
Is it safe to share your bank statements?
Landlords, lenders and accountants all ask for them. What is actually on the page, what to redact, and why black rectangles are not redaction.
APR vs interest rate: what you actually pay
Two numbers on every loan offer, and the smaller one is the one lenders advertise. Here is what separates them and which to compare on.
How to calculate VAT backwards from a gross total
Removing 20% VAT is not subtracting 20%. The arithmetic that trips up invoices, expense claims and pricing, explained once.
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