I recently received both rocky balboa and hitch on bluray from netflix. Both discs had a visible deeper scratch, starting on the outer perimeter and going in about 1/5 to 1/6 of an inch. Neither of these discs played in my samsung P1000, the player ejected them. Is this normal?, I thought a scratch like that on the outer edge would not affect the startup of a disc. Anybody with the same experiences?

Never seen a scratched blu-ray.

do you mean cracks or scratches???? do you know that one question mark is enough to make a sentence a question????

I would consider it a tiny crack I guess, as it can be seen going farely deep into the disc........................ Any ideas???????????????????????????????????????????????????????

I guess it would be caused by the deepness of the scratch. I have seen pictures of Talladega Nights being scratched to an insane amount with Steel wool and still playing. The protective layer on these discs is quite thick so I would assume that your scratch went down to the data layer and somehow busted it.

http://www.gizmowatch.com/entry/durabis-2-coating-helps-blu-ray-survive-steel-wool-use-abuse/

Durabis won't help the laser read through permanent marker...

Durabis won't help the laser read through permanent marker...
right, because permanent marker = a scratch

My copy of Superman Returns from Netflix was like this. A small crack on the edge, Blu-ray movie would not play. Did a disk buffer repair and still did not play.

/Returned to Netflix no problem
/It has only happened one time out of 11 Blu-rays from Netflix

________________________________________________________

I wish Netflix would not count a broken disk as a rental. Lost 3 days not having a replacement.

It's probably a crack and not a scratch. There have been other threads where people were receiving rental discs with small cracks at the edge of the disc, which are completely unplayable. I've received only one like this, fortunately. I haven't seen any reports of people buying discs that have been cracked like this.

Thanks for the feedback. The bluray discs I had def had cracks on the edges of the discs. At least I know my samsung player isnt going dead on me.

Kinda concerning though that a tiny crack on the outer edge would negate any kind of playback. I would think the outer edge would contain the extras and whatnot, and the inner part of the disc contain the actual movie. Maybe i have no idea what im talking about also.....

right, because permanent marker = a scratch
Why did you post a link to a page you didn't read? :confused:

I have my third Netflix disk with the tiny crack from the outside edge. (Saw III). This is getting annoying as time goes by.

This is why I buy instead of rent. 15 or 20 bucks and you can have a scratch free movie forever.

All I know is that my copy of Planet Earth was scratched and it froze a number of times. I returned it to Warner hoping that the scratches were the problem and not the disc authoring.

Knock on wood I have still been lucky with BBO.

I have seen discs that have tons of fingerprints on them, and generally look like they haven't been cared for.

None have skipped or jumped or refused to play.

I wonder which BD player is the most tolerant, how's the ps3 with edge cracked BR rented movies?

Never seen a scratched blu-ray.
I've seen plenty of them from Blockbuster rentals. They show scratches and fingerprints, just like dvds.

I wonder which BD player is the most tolerant, how's the ps3 with edge cracked BR rented movies?I have received a few BD disk from BBO with small cracks along the edge and they played fine on my PS3. I clean ALL my rental disk before using them. ;)

Casino Royal had some minor scratches which caused the movie to freeze at two points. I ended up watching the rest of the movie on my friends DVD. Honestly the BR was not head and shoulders better.

i'm amazed that more discs, regular DVD and BD are not unplayable given the paper envelop they use to mail these things. I personally would never put a disc in an envelop like this and mail it to you.

Of course any additional proctection will not only result in higher production costs, but also higher cost of mailing.......so, I'm sure that the risk of damaged discs has been accounted for by Netflix and deemed acceptable.

I have never received a scratched Blu Ray disc from Netflix, only smudges. However my Samsung will not play a disc with a smudge or small finger print, it will reject them or not load. Now regular DVDs and HD-DVD's I get scatches on from Netflix from time to time. I clean or buff them and they play fine.

The envelopes don't protect against cracks. I got a BD that was chipped on the edge, though it didn't affect playback.

Take a look at the top to see if you can see a visible crack.

Casino Royale just came to me from Netflix cracked and did not play. Buzzkill on Friday night, for sure. But I'll keep renting.

Welcome to the downside of using a hard coat. A harder disc will be harder to scratch, but easier to crack. For someplace like Netflix, they could buffer out a scratch, but you can't repair a crack.

Also, if you do scratch a Durabis coated disc, I don't think that scratch can be buffered out, at least using the buffers on the market today.

A harder disc will be harder to scratch, but easier to crack.And you have proof of this?


For the BD nay sayers: Do some testing of your own to prove how fragile BD are compared to HD-DVD, DVD and CD’s. Some wood blocks, felt, lab weights, sandpaper and steel wool should do the trick for surface testing. A small press or brake and a strain gage could be used for stress test. A freezer could be used for crack vs temperature theorist.

Have not received ANY defective BD disc from Netflix. Your history can be found under Your Account, then click Rental History.


Title Shipped Returned

Night at the Museum, 2006 05/03/2007 05/07/2007
Secret Window, 2004 04/27/2007 05/03/2007
A Scanner Darkly, 2006 04/23/2007 05/03/2007
The Devil Wears Prada, 2006 04/24/2007 04/27/2007
The Lake House, 2006 04/18/2007 04/24/2007
Stranger than Fiction, 2006 04/16/2007 04/19/2007
Payback, 1999 04/13/2007 04/18/2007
Eragon, 2006 04/09/2007 04/13/2007
Chicken Little, 2005 04/06/2007 04/12/2007
Relentless Enemies, 2006 04/03/2007 04/06/2007
Identity, 2003 04/03/2007 04/06/2007
Babel, 2006 03/29/2007 04/03/2007
Big Fish, 2003 03/30/2007 04/03/2007
Finding Neverland, 2004 03/26/2007 03/30/2007
The Prestige, 2006 03/23/2007 03/28/2007
The Departed, 2006 03/22/2007 03/26/2007
Flyboys, 2006 03/20/2007 03/23/2007
Mission: Impossible III, 2006 03/19/2007 03/22/2007
The Fifth Element, 1997 03/16/2007 03/20/2007
Layer Cake, 2004 03/15/2007 03/19/2007
The Omen 666, 2006 03/09/2007 03/15/2007
The Guardian, 2006 03/09/2007 03/15/2007
Black Hawk Down, 2001 03/06/2007 03/09/2007
The Last Waltz, 1978 03/05/2007 03/08/2007
Reign of Fire, 2002 02/28/2007 03/06/2007
District B13, 2004 03/01/2007 03/05/2007
Behind Enemy Lines, 2001 02/22/2007 03/01/2007
Ultraviolet, 2006 02/21/2007 02/27/2007
Open Season, 2006 02/16/2007 02/21/2007
The Sentinel, 2006 02/16/2007 02/21/2007
Pat Metheny: The Way Up 02/13/2007 02/16/2007
Bulletproof Monk, 2003 02/13/2007 02/16/2007
Crank, 2006 02/09/2007 02/13/2007
The Covenant, 2006 02/09/2007 02/13/2007
Chicago, 2002 02/06/2007 02/09/2007
Kiss Kiss Bang Bang, 2005 02/06/2007 02/09/2007

Testing isn't necessary as the answer to the question lies in simple properties of material 101.

If you take substance A and alter it through treatment to become harder, it also becomes more brittle. My statement is based on the understanding that the plastics used on HD DVD and BD discs are of the same family and very similar in physical properties prior to treatment. The BD coating is a chemical bond that alters the properties of the material. Hardness is inversly proportional to brittleness.

Testing isn't necessary as the answer to the question lies in simple properties of material 101.If you use that thesis then diamonds are more brittle than glass. I will pass this info to the drill head manufactures because I feel reasonably certain they will want to save a lot of money by making drill heads using glass.

I am not a plastic materials engineer, are you?

For a BD disc there is a 1.1-mm-thick substrate with a .1mm thick cover to the substrate (1.2mm total for the disc). This .1mm cover is a spin coat or a film that is applied to the substrate. This spin coat or film is what makes the disc scratch resistant. AFAIK, the substrate is similar to most other optical media. The substrate is 11 times the thickness of the cover coat. I will leave it to the experts to explain how the cover coat causes the substrate to crack on a BD.

For a BD disc there is a 1.1-mm-thick substrate with a .1mm thick cover to the substrate (1.2mm total for the disc). This .1mm cover is a spin coat or a film that is applied to the substrate. This spin coat or film is what makes the disc scratch resistant. AFAIK, the substrate is similar to most other optical media. The substrate is 11 times the thickness of the cover coat. I will leave it to the experts to explain how the cover coat causes the substrate to crack on a BD.

Because it is a chemical bond to the substrate, which alters the properties of the substrate. If it were not a chemical bond, then you would be able to remove the coating, or it would simply wear off over time.

If you use that thesis then diamonds are more brittle than glass. I will pass this info to the drill head manufactures because I feel reasonably certain they will want to save a lot of money by making drill heads using glass.

I am not a plastic materials engineer, are you?


Thanks for proving you have no idea what you are talking about. You couldn't have done a better job. A diamond is actually a very brittle material.

http://www.jewelrymall.com/diamond-guide.html

Diamonds are brittle: If you hit a diamond hard, they WILL crack or chip if mishandled. Don't wear your diamond when doing rough work.

A diamond is very hard, but also very brittle. Because it is hard, it makes a good cutting material, as it is harder than the material it is cutting. However, it is also very brittle, which means it can be easily broken (Diamonds are a bit harder to break than most brittle materials because of its isometric crystallography). This is why a diamond drill bit, for example, doesn't last forever.

The diamond drillbit is made of diamond fragments, each time a piece of diamond in the bit hits a material like steel, a small piece will chip and break-off (this helps to keep the cutting edge cooler too). Most bits are simply Diamond tipped, to help get the cut started on a hard material, like glass.

Diamond...hard but brittle. The same with a Durbis coated disc. Hard but brittle.

Diamond is a hardness of 10. A glass cubic Zirconium is a hardness of 8.3, so glass could be used as a substitute for Diamond, except Diamond has a higher thermal transfer property than CZ, which would make CZ a poor choice for a drillbit. but glass can be nearly as hard as diamond, and likewise, brittle.

Moissanite can be almost as hard as diamond (9.25) and has excellent thermal transfer properties, and would be a better silicone based, glass like substance for a drill bit.

Because it is a chemical bond to the substrate, which alters the properties of the substrate. If it were not a chemical bond, then you would be able to remove the coating, or it would simply wear off over time.What properties of the substrate have been altered? Painting metal is also a chemical bond but does not change the properties of the metal.

Thanks for proving you have no idea what you are talking about. You couldn't have done a better job.It may come as a surprise to you but I can do searches on various materials as well.

And again, I am not a materials engineer, are you?

Then why didn't you before you made your misinformed post?

What properties of the substrate have been altered? Painting metal is also a chemical bond but does not change the properties of the metal.

Once again, your lack of knowledge shows. Most paints (the majority, only a few specialty paints fall outside this realm) do not utilize a chemical bond with the surface being painted.

Most paints use a mechanical bond. The structure of the paint fills in and grabs surface imperfections in the surface being painted. This is the case with your metals etc. If you try using this type of paint on a plastic (or metal) surface with an extremely high surface finish, the paint will just bead on run-off. It won't adhere. It isn't a chemical bond, just a failed mechanical bond. To paint a smooth surface finish plastic, there are specialty paints that form a chemical bond with the plastic, but alter the properties of the plastic somewhat in doing so.

Since you refer to painting metal, you are probably referring to painting items like cars, planes, refrigerators etc (planes are probably fibreglass, but the same principle applies). These items use a process where a primer is applied first. This primer utilizes a mechanical bond to adhere to the surface being painted. Then the color coat is applied to the primer. The color coat then chemically bonds to the primer, and subsequent coats of paint, clear coat, etc. will chemically bond to the layer of paint below it. However, these paints are not chemically bonding to the original substrate, thus they do not alter the properties of the substrate.

You should really stick to talking about stuff you know...

Once again, your lack of knowledge shows.So does yours. For the third time: And again, I am not a materials engineer, are you?

I used the words "chemical bond" when "chemical process" was intended. Regardless, a cover (paint process) has been applied and it does not alter the metal (substrate). You have not provided any evidence as to why a 100μm cover bonded to 1100μm substrate will cause the assembly to crack.

Since you imply you are so knowledgeable in the area BD replication, give us a step by step process of how a BD is manufactured and why they are prone to cracking. Do you believe the Taber abrasion test is sufficient or should another test method be used by the BDA? If so, why?

So you will know, I have most of the white papers published by the BDA. The manufacturing process is covered in detail.

Now as to your paint beading problem. Try lightly sanding with 500 grit. Test paint. Still beading, try 400 grit.

So does yours. For the third time: And again, I am not a materials engineer, are you?

I used the words "chemical bond" when "chemical process" was intended. Regardless, a cover (paint process) has been applied and it does not alter the metal (substrate). You have not provided any evidence as to why a 100μm cover bonded to 1100μm substrate will cause the assembly to crack.

Since you imply you are so knowledgeable in the area BD replication, give us a step by step process of how a BD is manufactured and why they are prone to cracking. Do you believe the Taber abrasion test is sufficient or should another test method be used by the BDA? If so, why?

So you will know, I have most of the white papers published by the BDA. The manufacturing process is covered in detail.

Now as to your paint beading problem. Try lightly sanding with 500 grit. Test paint. Still beading, try 400 grit.

Yes, sanding works because paint is a mechanical bond, not a chemical bond. The only "chemical process" that occurs is the drying of the paint.

If you want a step by step of how a Durabis disc is manufactured, just refer to the patent. I don't have the time or the space to regurgitate it all.

http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220050248881%22.PGNR.&OS=DN/20050248881&RS=DN/20050248881

Also, why are you talking about abrasion tests? Cracking has nothing to do with abrasion. I've already said the disc has a high hardness, this is resistant to abrasion. No one disputes that.

What you seem to be opposed to is the claim that making the disc harder, also makes it more brittle. Look through your BDA white papers and look for information on flexural testing, Charpy impact, Gardner impact testing, Gravelometer (if you want to test for chipping, not cracking), perhaps compressive plate testing, Dynatup impact (probably not a real world condition, a high speed puncture), Izod impact test (eitehr notched or unnotched), shear testing, or tensile impact testing. These are all tests that could potentially show a difference in brittleness.

Since we are talking about discs being cracked by being sent through the mail, several of the above tests would not reflect a real world condition (notched Izod, tensile impact testing, gravelometer), at least not one I could think of. A few other tests, such as the Dynatup, also probably don't reflect a real world condition, or if they do, it would be a rare one (somehow a metal rod falls from a shelf and impacts a disc that happens to be laying flat against a hard surface, or someone shoots at a postal truck and a disc gets hit by the bullet, etc.).

Other tests probably do reflect a real world condtion, like compressive plate testing. In the real world, a heavy package accidentally gets set on top of a bin containing some mail. Somewhere in the mail is a netflix disc, which gets compressed by the heavy package. Definately sheer testing (part of the disc is overhung and has a force applied to it, or is struck by an impact, ala the disc becomes a diving board of sorts). Flexural testing and some of the other impact tests would also reflect real world scenarios.

Also keep in mind that even if the crack doesn't propegate through the entire cross section of the disc, a crack in just the Durabis would render the disc unreadable.

What you seem to be opposed to is the claim that making the disc harder, also makes it more brittle.Not true, I can see where the 100μm cover may be more brittle. The 1100μm substrate should be unchanged. This combo (1200μm) may make it a little more prone to "cracking" than a CD or HD DVD. Till a reputable group does some scientific testing of these media formats and proves that BD are more prone to “cracking” than the other formats then the exaggerated claims about “cracking” are just that.

You have mentioned Durabis several times. Do you know for a fact that current BD-ROM production is using Durabis? Or film cover? Or spin coat?

Not true, I can see where the 100μm cover may be more brittle. The 1100μm substrate should be unchanged. This combo (1200μm) may make it a little more prone to "cracking" than a CD or HD DVD. Till a reputable group does some scientific testing of these media formats and proves that BD are more prone to “cracking” than the other formats then the exaggerated claims about “cracking” are just that.

You have mentioned Durabis several times. Do you know for a fact that current BD-ROM production is using Durabis? Or film cover? Or spin coat?


A few discs have used Durabis, and I believe recordable media uses Durabis, but most BD-ROM discs have used an alternative to Durabis that is the same in concept. The layer is applied with a spin coat. I believe the primary hard coating used to date is the one used on Sony's AccuCore line of discs. This hardcoat has been shown by TDK to have a lower performance when compared to Durabis. So I guess maybe those discs aren't quite as hard, which means they are less brittle.

A film cover has been proven not to work due to shrinkage. Yields become extremely low when a film cover is attempted.

TDK has done research on the brittleness of BD-ROM discs and they have not made the results of those tests public. Yet they are willing to flaunt their hardness test results every chance they get. To me, this is all the confirmation that I need that the discs are indeed more brittle.

However, the fact that they are more brittle doesn't mean they are too brittle. For typical consumer use, it probably will never be a problem. However, for rental markets like Netflix, where the discs are frequently moved in paper mailers, this definately could become a problem. I know the discs are more brittle, and if they have a lower flexural fatigue strength, then the combination could result in a comparitively short lifespan at services like Netflix

This is just to give you the score so far...

wnorris: 07
Wendell: zero

Get'im tiger! LOLOLOL

Till a reputable group does some scientific testing of these media formats and proves that BD are more prone to “cracking” than the other formats

How many reports and images have you seen of edge-cracked DVDs and HD DVDs? How many have you seen of Blu-rays?

...

In my experience, BD discs are being damaged on a much higher scale than DVD's.

Look at some of my recent history, all movies are BD:

Casino Royale, 2006 05/02/07 05/09/07 Report Problem

Corpse Bride, 2005 05/03/07 05/09/07 Report Problem

Black Hawk Down, 2001 04/19/07 05/03/07 Report Problem

A Scanner Darkly, 2006
Original Shipment (Reported damaged on 04/17/07.) 04/16/07 04/19/07
Replacement Shipment 04/18/07 05/03/07 Report Problem

Silent Hill, 2006 04/18/07 05/02/07 Report Problem

XXX: Special Edition, 2002
Original Shipment (Reported damaged on 04/09/07.) 04/06/07 04/11/07
Replacement Shipment (Reported damaged on 04/11/07.) 04/10/07 04/16/07
Replacement Shipment (Reported damaged on 04/13/07.) 04/12/07 04/16/07
Replacement Shipment (Reported mislabeled on 04/17/07.) 04/16/07 04/19/07

Payback, 1999 04/11/07 04/18/07 Report Problem

The Prestige, 2006
Original Shipment (Reported damaged on 04/08/07.) 04/04/07 04/11/07
Replacement Shipment 04/09/07 04/16/07 Report Problem

Reign of Fire, 2002 04/06/07 04/11/07 Report Problem

Last 31-90 Days

Vertical Limit, 2000 03/19/07 04/06/07

Bulletproof Monk, 2003 03/26/07 04/06/07

Aeon Flux, 2005 03/27/07 04/04/07

Species, 1995
Original Shipment (Reported damaged on 03/16/07.) 03/13/07 03/19/07
Replacement Shipment 03/19/07 03/26/07

Syriana, 2005 03/16/07 03/26/07

The Fifth Element, 1997
Original Shipment (Reported damaged on 03/08/07.) 03/07/07 03/14/07
Replacement Shipment 03/12/07 03/19/07

The Descent, 2006
Original Shipment (Reported damaged on 03/08/07.) 03/07/07 03/14/07
Replacement Shipment 03/12/07 03/16/07

In fact, Netflix has acknowledged the vast number of damaged discs theyve sent me and given me a long term discount.

In my experience, BD discs are being damaged on a much higher scale than DVD's.

Look at some of my recent history, all movies are BD:

Casino Royale, 2006 05/02/07 05/09/07 Report Problem

Corpse Bride, 2005 05/03/07 05/09/07 Report Problem

Black Hawk Down, 2001 04/19/07 05/03/07 Report Problem

A Scanner Darkly, 2006
Original Shipment (Reported damaged on 04/17/07.) 04/16/07 04/19/07
Replacement Shipment 04/18/07 05/03/07 Report Problem

Silent Hill, 2006 04/18/07 05/02/07 Report Problem

XXX: Special Edition, 2002
Original Shipment (Reported damaged on 04/09/07.) 04/06/07 04/11/07
Replacement Shipment (Reported damaged on 04/11/07.) 04/10/07 04/16/07
Replacement Shipment (Reported damaged on 04/13/07.) 04/12/07 04/16/07
Replacement Shipment (Reported mislabeled on 04/17/07.) 04/16/07 04/19/07

Payback, 1999 04/11/07 04/18/07 Report Problem

The Prestige, 2006
Original Shipment (Reported damaged on 04/08/07.) 04/04/07 04/11/07
Replacement Shipment 04/09/07 04/16/07 Report Problem

Reign of Fire, 2002 04/06/07 04/11/07 Report Problem

Last 31-90 Days

Vertical Limit, 2000 03/19/07 04/06/07

Bulletproof Monk, 2003 03/26/07 04/06/07

Aeon Flux, 2005 03/27/07 04/04/07

Species, 1995
Original Shipment (Reported damaged on 03/16/07.) 03/13/07 03/19/07
Replacement Shipment 03/19/07 03/26/07

Syriana, 2005 03/16/07 03/26/07

The Fifth Element, 1997
Original Shipment (Reported damaged on 03/08/07.) 03/07/07 03/14/07
Replacement Shipment 03/12/07 03/19/07

The Descent, 2006
Original Shipment (Reported damaged on 03/08/07.) 03/07/07 03/14/07
Replacement Shipment 03/12/07 03/16/07

In fact, Netflix has acknowledged the vast number of damaged discs theyve sent me and given me a long term discount.

Maybe you should try the BBO trial.

Luckily I have had no problems so far on 20+ BDs

I haven't had a single problem with the 10, or so, Blu Ray discs I've rented from NetFlix.

I wonder if there is a problem with certain mail facilities that are damaging discs when they are shipped.


EDIT: Oh, and AWESOME nerd fight.

A clarification on several points may be in order. 1- I have stated several times that I am not a materials engineer. There is two links in my signature line that will provide some info on me. 2- The agreement on definitions of terms, from Oxford University Press:
brittle >adjective 1 hard but liable to break or shatter easily. 2 hard or superficial in a way that masks nervousness or instability. >noun a brittle sweet made from nuts and set melted sugar.

-ORIGIN related to an Old English word meaning 'break up'.Just so I understand correctly, a freeze dried flower pedal will shatter at the slightest touch. Does that mean it is super hard? Or is it just an exception to the rule?

3- This statement ran up the red flag for me:Because it is a chemical bond to the substrate, which alters the properties of the substrate.The substrate has a reflective layer that is applied to it by Sputtering. The cover layer is applied to this composite and cured by UV. Lastly, the hard coat is applied to the cover layer. Therefore I fail to see how the substrate properties could be altered by the hard coat and wnorris has not provided any proof that it has been altered.

4- The 1100μm substrate and the 100μm cover makeup the composite disc. What is not defined in the white papers is how the composite cover layer is formed. It could be 90μm of UV Resin with 10μm of materials that forms the outer hard coat. If true, my money is on a disc that varies VERY little from that of a DVD in terms of how brittle it is. If the entire 100μm cover layer makes up the hard coat it still should not alter the composite drastically.


Confusing: :confused:
However, the fact that they are more brittle doesn't mean they are too brittle. For typical consumer use, it probably will never be a problem. However, for rental markets like Netflix, where the discs are frequently moved in paper mailers, this definately could become a problem. I know the discs are more brittle, and if they have a lower flexural fatigue strength, then the combination could result in a comparitively short lifespan at services like NetflixIf you have the knowledge of these materials and how to stress test them, why not do so and publish your results? You do a disservice to AVS readers by continuing to make such post. Is it not standard scientific practice to do test and have others confirm the results of those test?

A simple test: I took a BD and placed ½ the disc, label up, on a hard surface and pressed ↓ on the outer edge to a delflection of ≈ 19mm (≈ ¾”). This was repeated three times. There was no visible damage using a 3x handheld glass for inspection. Next the disc was viewed (including the extras) and there was no playback problems.

For the statisticians: Some have claimed a high percentage of their BD Netflix rentals have arrived that had damaging “cracks”, many others have claimed they have no problems with their BD Netflix rentals. What is the probability that for every 30 disc rented some have no problems while others have 10 or more disc with problems?

Closing: I am going to ask Netflix if they would provide damage data on the various media disc they rent. I highly doubt they will, but I will ask anyway.

This is just to give you the score so far...

wnorris: 07
Wendell: zero

Get'im tiger! LOLOLOL

QFT

After this last post by Wendell

wnorris: 07
Wendell: -1

And i agree with bassmonkeee,

Great Nerd fight.

For a BD disc there is a 1.1-mm-thick substrate with a .1mm thick cover to the substrate (1.2mm total for the disc). This .1mm cover is a spin coat or a film that is applied to the substrate. This spin coat or film is what makes the disc scratch resistant. AFAIK, the substrate is similar to most other optical media. The substrate is 11 times the thickness of the cover coat. I will leave it to the experts to explain how the cover coat causes the substrate to crack on a BD.

the scratch resistent layer is much smaller then .1mm

ps .1mm is the datalayers + HC