I bought a new blade -Stiga Carbonado 145  with rubbers from tabletennis11 and let tabletennis11 to glue them. 

When I got the blade, I found the back hand rubber Donic Bluefire M2 is really not even. Here is the picture. I contact tabletennis11 through email. And what I got is "Please don't worry, it is a normal quality of this rubber and it will not affect the game". Do you think the rubber is "Normal Quality"?  

I got answer from Donic and Tabletennis11. Looks it is my ignorance.

“ ...All rubbers with a big pore sponge have this uneven-looking surface due to the big pores. ..."

"The unevenness perceived by the human eye is much bigger than the actual unevenness when measured, meaning that the surface as far as playing properties are concerned can be regarded as smooth."

By the way, I am happy on the service of tabletennis11. Price is good and the shipping is fast. 

My CONCLUSION:

From the information I got from this thread and my friends's help. Here is my conclusion and thought.

1. The big pore sponge does have the unevenness problem after gluing. 

    - The look is more exaggerated on black rubbers. It's still there on the red rubbers, but very faintly
    - this "look" will not go away
    - re-gluing does not help 

    - the unevenness may not affect the play. Here are some pictures of PRO's paddles

       https://www.tabletennisdaily.com/forum/showthread.php?7663-Bats-of-the-German-League-Players-Gallery!

    - the unevenness may depend on the glue brand and glue process.

      "Any large cell sponge in combination with very aggressive type water glue has the possibility of this effect, the large cells at the base collapse because they get full of glue, this causes a ripple effect through the bubbles of the sponge and you can see this "push pull" effect, the pips are now slightly aimed different directions causing disruptions on the top of the rubber. I am sure it is perfectly playable however the engineering of this rubber was intended for the pips to all be oriented perfectly and uniformly outward. 

Water base glues leave lots of product in the cells of the sponge, the ones that dry "gummy" are the worst offenders." --- zeropong from this thread

2.  The unevenness may also depend on batches of the product. Some batches may not have the problem; Some does.

3. Here are some products that I have pictures showing unevenness

    a. Donic bluefire M2

    b. TIBHAR MX-P

    c. TiBHAR EL-P 

4.  Other products that claimed has the similar problem

    Andro Rasant, Rasant Grip, max black OmegaV Tour

My suggestion is 

1. The manufactures should improve the Quality Control. ( My understanding is the unevenness is due to pores in the sponge distributed unevenly, then the stress from the gluing process makes this unevenness) 

2. Manufactures should publish the standard for this unevenness; distinguish the good patches and bad patches. Marks the different level like PingPong ball, for example training rubber, tournament rubber.

Edited by seanlin1971 - 12/02/2017 at 12:31pm

Just reglue it yourself.

I actually re-glued it tonight. It does not help.

i can't see anything wrong from that picture; the lighting makes it hard to see the surface of the rubber.

People like wasting time over stuff that doesn't affect how well they play table tennis.  Seriously.

It's normal

I'm glad someone brought this up

seanlin: 

- it is normal.  Most likely due to the slightly larger pores as someone said above.

- I've seen this look like little bumps. But not bumps on surface of topsheet. If you hold the blade with rubber up to your eye-level, you'll see the topsheet is actually flat, no bumps at all.

- your photo view is same as I look at my rubbers and seeing the same thing, but no bumps. If it's not the larger pores, then it's glue-shadow. No worries, topsheet is still flat surface.

- I've seen this on my Andro Rasant, Rasant Grip. The look is more exaggerated on black rubbers. It's still there on the red rubbers, but very faintly

- this "look" will not go away

- re-gluing does not help

Other brands I saw this:  2.1 red Evolution MX-P,  max black OmegaV Tour

If your topsheet is flat with glue-shadow, it wont affect your play

Another factor I blame is the crappy glue I've been using:  Revolution No. 3 - normal viscosity. It's like water or milk. I have to put at least 2 layers. That's for another thread

Thanks. I update my post based on Donic and tabletennis11's answer.

Does the rubber feel even? I've never seen this effect before but I haven't seen the Donic M2 on blades at my club. Are all large pore rubbers like this or only certain batches?

Edited by richrf - 12/01/2017 at 7:54am

seanlin1971 wrote: I have no idea ""Are all large pore rubbers like this or only certain batches? "But my friend tried MX-P yesterday, it has the similar unevenness. What he "noticed more so on the black rubbers than on red"

When you say unevenness, are you speaking strictly abound visual appearance or also about how it feels to the touch? Thanks.

Edited by richrf - 12/01/2017 at 8:02am

seanlin1971 wrote: Honestly, hard to tell. From theory ( I am an engineer :)), if there is visual appearance uneveness, there will be actually unevenness. That is how some measure machines work.

Thanks. This seems reasonable since any optical effect would necessarily imply uneven surfaces but do you actually feel something? Still curious whether it is only certain batches it all batches? If someone has M2 without this effect it would answer the question.

seanlin1971 wrote: When I play with it, I donot feel difference. But when I look at it, . I think it is just psychological effect.

Thanks. Good luck with your new racket!

Off-topic, how does the blade play and which one were you using before? I ask because I'm interested in this blade :P

seanlin1971 wrote: unstopabl3 wrote: Off-topic, how does the blade play and which one were you using before? I ask because I'm interested in this blade :P My previous paddle is Stiga CL CR  FH: DHS hurricane 3 NEO BH: butterfly Siriver EL Current: stiga carbonado 145 FH: DHS hurricane 3 NEO BH: Donic bluefire M2 I just played once on stiga 145 and feel good on it so far. Compare to the clipper CL, I feel 1. It is faster than Clipper. 2. To block the ball, Need less action. 3. I may need to just my action on my FH loop, it is not spin as much as Clipper, but faster. 4. No much difference on the BH, but faster. As the bluefire M2 is faster than Siriver EL. So, hard to tell if it is due the blade.  5. I thought the surface may be too hard to control, but donot feel it is hard to control.  So far so good, but it is my opinion.

Great reply, how does it feel? Does it have a muted feel like a Viscaria or does it have a good feel with some feedback like a timo boll alc??? Also how is the handle and how is the craftmanship?

Thanks

It’s normal, all my Donic rubbers look like that, even the new Bluestorm