Answers.Body: <p>From TLG Customer Service (emphasis added by me for one possible explanation):</p>
  
  <blockquote>
    <p>I truly appreciate that you sent this to us so that we could see the variation
    in the parts. Being able to see the numbers on the inside was very
    helpful!</p>
    
    <p>We haven't had any reports about quality issues with this element for
    any of the pressings. I've actually taken the link you provided and,
    as you know, the LEGO® Quality Team takes the quality of our products
    very seriously, and our team will now be able to look at these images
    in the post and make further evaluations. <strong>It could be that the mould
    was changed and the new mould hasn't worn smooth yet</strong> but I can't say
    for certain that that would be the cause of the variation in the
    texture on the top of the tile.</p>
    
    <p>Please make sure the user doesn't delete the post so that our Quality
    Team can take a look.</p>
    
    <p>Thank you again for passing this important post along to us. We really
    appreciate it!</p>
  </blockquote>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-02T20:20:11.917Z
Answers.Text: Have you heard any news from TLG?
Answers.UserDisplayName: Metalbeard
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-02T20:47:50.057Z
Answers.Text: @Aziraphale Nothing since I've posted this, I'm afraid.
Answers.UserDisplayName: jncraton
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-15T23:13:00.630Z
Answers.Text: It seems that TLG didn't come to a conclusion, or it was not important enough to get back to you.
Answers.UserDisplayName: Metalbeard
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-11-17T20:33:38.617Z
Answers.Text: I didn't know that TLG is so responsive to these kind of questions. I assume that you will post the final results? Does TLG even have a user here??
Answers.UserDisplayName: Metalbeard
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-11-17T20:58:46.067Z
Answers.Text: I'll definitely update this answer if I hear any more details. TLG takes quality very seriously. I've never seen anyone post here officially representing TLG, but I'd certainly be happy to see that. It's tricky on their end, as there is significant media training that employees need to go through to speak publicly for the company.
Answers.UserDisplayName: jncraton
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-11-17T20:24:45.723Z
Answers.LastActivityDate: 2017-11-17T20:24:45.723Z
Answers.UserDisplayName: jncraton
Body: <p>Recently, I filled a PAB cup in the nearest LEGO store. Among other parts, I also took a lot of light bluish grey 2x2 tiles. The following image shows some of these:</p>
  
  <p><a href="https://i.sstatic.net/LZvnh.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/LZvnh.jpg" alt="No difference visible from this angle"></a></p>
  
  <p>However, reflected light reveals that the surface of the tiles can be quite different. This image (same parts as above) shows that there are obviously two types of tiles. One with a really smooth surface, with the stud ring on the underside visible from above. And one with a rough surface similar to brushed metal: </p>
  
  <p><a href="https://i.sstatic.net/RrdKQ.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/RrdKQ.jpg" alt="enter image description here"></a></p>
  
  <p>I am a bit surprised to see LEGO products with their sub-micrometer precision molds showing such behaviour. Are different production lines mixing here? Have you experienced other parts with different properties that should be the same?</p>
  
  <p><strong>Update:</strong></p>
  
  <p>Alexander O'Mara suggested to examine the underside, and indeed there are some patterns. First, the smooth tiles:
  <a href="https://i.sstatic.net/mZos2.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/mZos2.jpg" alt="underside of smooth tiles"></a></p>
  
  <p>Now the "brushed" tiles:
  <a href="https://i.sstatic.net/3xiKy.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/3xiKy.jpg" alt="enter image description here"></a></p>
  
  <p>You notice the groove above the word LEGO on the smooth tiles that the brushed tiles don't have. The number 3068 is of course the same on both. There is a lot number (?) in the format XX-YY with YY being underlined.</p>
  
  <p>The smooth tiles all have XX-57 with varying XX (right hand side), the brushed tiles all have XX-49 with varying XX (lower side, next to the "3068").  </p>
  
  <p>So, what does that mean?</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>One observation: inside the bottom tube, the surface shows a structure in the smooth tiles, but no structure in the "brushed" tiles. This could mean that the 3068 tile consists of two pieces that are hot-glued together in the process: One part covering the upper surface and sides, and another piece with the bottom tube and inside. The upper, covering part (from which small pieces are stamped out) may itself have an upper and lower side with slightly differing roughness. Maybe the production process doesn't prefer which side is up, so sometimes a rough side can be seen, and sometimes not. This is only a theory. </p>
  
  <p>Can someone point towards an answer?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-15T03:46:17.173Z
Comments.Text: Do the undersides between them distinguishable at all? I wonder if there are different versions of the mold.
Comments.UserDisplayName: Alexander O'Mara
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-15T11:11:00.263Z
Comments.Text: Good point. I will have a closer look and update the question today.
Comments.UserDisplayName: Metalbeard
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-16T19:56:53.673Z
Comments.Text: The XX-XX numbers I believe identify the mold that made the piece (so if they get defective ones, they know which mold has a problem). Possibly The second half of the number identifies a version of the mold? I wonder if perhaps one version is/was used for painted or sticker pieces (I know it seems weird to have a different piece for stickers, but I've seen them provide smoother roof tiles for stickers, sometimes with a mix in the same set).
Comments.UserDisplayName: Alexander O'Mara
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-17T07:35:11.657Z
Comments.Text: Do you mean slope bricks or tiles that are used on roofs?
Comments.UserDisplayName: Metalbeard
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-17T08:11:11.990Z
Comments.Text: I mean the sloped bricks.
Comments.UserDisplayName: Alexander O'Mara
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-17T08:50:27.220Z
Comments.Text: That is indeed interesting, because most of the slopes with stickers have the usual grainy surface of slope bricks. Do you mean that there are e.g. 45 2x2 slope bricks with a smooth surface?
Comments.UserDisplayName: Metalbeard
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-17T09:04:13.613Z
Comments.Text: Not entirely smooth, just about half the texture of the regular roof tiles (unless all roof tiles are like that now, I'm not sure). I remember the Dino Attack Iron Predator having 4 2x2x3 slopes, 2 with less texture, to which the stickers would stick better (the other 2 did not get stickers), though the instructions did not mention it.
Comments.UserDisplayName: Alexander O'Mara
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-17T21:23:44.107Z
Comments.Text: Interesting. I looked at my sorted Tile 2x2 in light bluish gray and all have smooth tops. Mold numbers are XX-47 (without slot above logo) and XX-53 (with slot above logo).
Comments.UserDisplayName: Phil B.
Tags: <piece-information><manufacturing><pick-a-brick>
Title: Different surface roughness of tiles. Quality issue?
UserDisplayName: Metalbeard
ThreadText: # Different surface roughness of tiles. Quality issue?
  
  (Asked by: username_0 on 2017-11-14)
  
  Recently, I filled a PAB cup in the nearest LEGO store. Among other parts, I also took a lot of light bluish grey 2x2 tiles. The following image shows some of these:
  
  [![No difference visible from this angle](https://i.sstatic.net/LZvnh.jpg)](https://i.sstatic.net/LZvnh.jpg)
  
  However, reflected light reveals that the surface of the tiles can be quite different. This image (same parts as above) shows that there are obviously two types of tiles. One with a really smooth surface, with the stud ring on the underside visible from above. And one with a rough surface similar to brushed metal:
  
  [![enter image description here](https://i.sstatic.net/RrdKQ.jpg)](https://i.sstatic.net/RrdKQ.jpg)
  
  I am a bit surprised to see LEGO products with their sub-micrometer precision molds showing such behaviour. Are different production lines mixing here? Have you experienced other parts with different properties that should be the same?
  
  **Update:**
  
  username_1 username_1 suggested to examine the underside, and indeed there are some patterns. First, the smooth tiles:
  [![underside of smooth tiles](https://i.sstatic.net/mZos2.jpg)](https://i.sstatic.net/mZos2.jpg)
  
  Now the "brushed" tiles:
  [![enter image description here](https://i.sstatic.net/3xiKy.jpg)](https://i.sstatic.net/3xiKy.jpg)
  
  You notice the groove above the word LEGO on the smooth tiles that the brushed tiles don't have. The number 3068 is of course the same on both. There is a lot number (?) in the format XX-YY with YY being underlined.
  
  The smooth tiles all have XX-57 with varying XX (right hand side), the brushed tiles all have XX-49 with varying XX (lower side, next to the "3068").
  
  So, what does that mean?
  
  **EDIT:**
  
  One observation: inside the bottom tube, the surface shows a structure in the smooth tiles, but no structure in the "brushed" tiles. This could mean that the 3068 tile consists of two pieces that are hot-glued together in the process: One part covering the upper surface and sides, and another piece with the bottom tube and inside. The upper, covering part (from which small pieces are stamped out) may itself have an upper and lower side with slightly differing roughness. Maybe the production process doesn't prefer which side is up, so sometimes a rough side can be seen, and sometimes not. This is only a theory.
  
  Can someone point towards an answer?
  
  **Tags:** piece-information, manufacturing, pick-a-brick
  
  > **Comments:**
  > **username_1**: Do the undersides between them distinguishable at all? I wonder if there are different versions of the mold.  
  > **username_0**: Good point. I will have a closer look and update the question today.  
  > **username_1**: The XX-XX numbers I believe identify the mold that made the piece (so if they get defective ones, they know which mold has a problem). Possibly The second half of the number identifies a version of the mold? I wonder if perhaps one version is/was used for painted or sticker pieces (I know it seems weird to have a different piece for stickers, but I've seen them provide smoother roof tiles for stickers, sometimes with a mix in the same set).  
  > **username_0**: Do you mean slope bricks or tiles that are used on roofs?  
  > **username_1**: I mean the sloped bricks.  
  > **username_0**: That is indeed interesting, because most of the slopes with stickers have the usual grainy surface of slope bricks. Do you mean that there are e.g. 45 2x2 slope bricks with a smooth surface?  
  > **username_1**: Not entirely smooth, just about half the texture of the regular roof tiles (unless all roof tiles are like that now, I'm not sure). I remember the Dino Attack Iron Predator having 4 2x2x3 slopes, 2 with less texture, to which the stickers would stick better (the other 2 did not get stickers), though the instructions did not mention it.  
  > **username_2**: Interesting. I looked at my sorted Tile 2x2 in light bluish gray and all have smooth tops. Mold numbers are XX-47 (without slot above logo) and XX-53 (with slot above logo).  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_3 on 2017-11-17. Score: 7 | Accepted answer
  
  From TLG Customer Service (emphasis added by me for one possible explanation):
  
  > I truly appreciate that you sent this to us so that we could see the variation
  > in the parts. Being able to see the numbers on the inside was very
  > helpful!
  >
  > We haven't had any reports about quality issues with this element for
  > any of the pressings. I've actually taken the link you provided and,
  > as you know, the LEGO® Quality Team takes the quality of our products
  > very seriously, and our team will now be able to look at these images
  > in the post and make further evaluations. **It could be that the mould
  > was changed and the new mould hasn't worn smooth yet** but I can't say
  > for certain that that would be the cause of the variation in the
  > texture on the top of the tile.
  >
  > Please make sure the user doesn't delete the post so that our Quality
  > Team can take a look.
  >
  > Thank you again for passing this important post along to us. We really
  > appreciate it!
  
  > **Comments:**
  > **username_0**: I didn't know that TLG is so responsive to these kind of questions. I assume that you will post the final results? Does TLG even have a user here??  
  > **username_3**: I'll definitely update this answer if I hear any more details. TLG takes quality very seriously. I've never seen anyone post here officially representing TLG, but I'd certainly be happy to see that. It's tricky on their end, as there is significant media training that employees need to go through to speak publicly for the company.  
  > **username_0**: Have you heard any news from TLG?  
  > **username_3**: @Aziraphale Nothing since I've posted this, I'm afraid.  
  > **username_0**: It seems that TLG didn't come to a conclusion, or it was not important enough to get back to you.  
  
  ---
  
  