Why Did Book Covering Suddenly Start Bubbling? We Went Looking for Answers
For years, adhesive book covering did exactly what it was supposed to do. It went on smoothly, could be repositioned while covering, and then developed a secure bond to protect the book underneath.
Then something changed.
When the Problem First Appeared
Several years ago, we began seeing a strange problem. Books would be covered beautifully and look perfectly fine when finished. But two or three days later, large bubbles could appear and the covering would begin lifting away from the book.
And it wasn't just happening to us.
The same problem was being experienced across the book-covering industry, which raised an obvious question:
What had changed?
Was it the adhesive - or had books changed too?
Has Modern Book Covers Changed?
At the time, we heard that changes to the finishes being used on book covers could be contributing to the problem.
Modern books can have many different finishes - gloss, matt, soft-touch, anti-scuff and other coatings designed to make them look and feel better and withstand handling.
Some of these finishes can also make the surface more difficult for an adhesive to bond to.
Someone once described the newer surfaces to us as being almost “Teflon-like”. They weren't actually coated in Teflon, but it was a simple way of describing a surface that an adhesive could have more difficulty gripping.
This could help explain something that had puzzled us for years: why did the covering look perfect when it was first applied, but start bubbling days later?
The Industry Tried to Solve the Problem
One response was a move from solvent-based adhesives to water-based adhesives.
This helped with some of the adhesion problems, but we noticed something else had changed.
The delayed bond wasn't the same.
Delayed bond is what gives you time to position the covering, lift it if necessary and smooth out bubbles before the adhesive develops its stronger bond.
For anyone covering large numbers of books, particularly schools and libraries, that little bit of extra working time can make a big difference.
So We Started Looking for Something Better
At Vipa, we eventually decided to source our adhesive book covering directly.
We tested different films, adhesives and samples because we wanted two things:
A covering that performs reliably - and enough delayed bond to make it forgiving and easy to apply.
Our current Vipaseal uses a CPP (cast polypropylene) film with a solvent-based adhesive formulation and has been performing extremely well.
BOPP vs CPP – Why the Film Matters
Not all polypropylene films behave the same way. BOPP (Biaxially Oriented Polypropylene) is stretched in two directions during manufacture. This gives it excellent clarity, strength and gloss, but the stretching can also leave the film with a degree of internal stress or “memory.” Under certain conditions, the film can have a tendency to contract as those stresses relax.
CPP (Cast Polypropylene) is manufactured differently and is not stretched and oriented in the same way. As a result, it generally has lower internal shrink stress and less tendency to pull back towards an earlier state. It is also softer and more flexible, allowing it to conform readily to a book's surface.
This doesn't mean BOPP automatically causes bubbling — adhesive chemistry, book-cover finishes and surface compatibility are also extremely important. However, film movement and residual stress can place additional strain on an adhesive bond, particularly where adhesion to the book surface is already difficult.
But What Actually Caused the Original Problem?
Our experience left us curious about what actually caused the original industry problem.
So we've started investigating it.
We're now looking at different modern book-cover finishes and commercial laminates to better understand how they interact with pressure-sensitive adhesives.
Interestingly, recent Australian industry information has also highlighted the challenges that some modern book finishes can create for adhesive covering — including problems that may not become apparent until 24–72 hours after application.
That's remarkably similar to what we witnessed ourselves years ago.
Why Does This Matter?
Because good book covering isn't simply about making something as sticky as possible.
If an adhesive grabs too aggressively, covering a book can become frustrating. Once it touches the surface, there's little opportunity to correct it.
For us, the ideal book covering needs to strike a balance.
It should give you enough time to position and smooth the film during application — and then develop the bond needed to protect the book.
We're Still Investigating
After supplying book covering to Australian schools and libraries for many years, we've learned that sometimes the smallest details make the biggest difference.
And we're still curious.
As our testing continues, we'll share what we discover about modern book-cover finishes, adhesives and why some books can be much more challenging to cover than others.