Originally Posted by tiddler
Cynical2 has also tried it over a gray base with good results despite some application difficulties. Maybe Cynical2 would comment on that (good or bad).
Since my name was brought up as an example of someone whose used the Folkart Pearlizing Medium topcoat, I feel obliged to respond.
Some background: For my first DIY screen, I used an EF-04 base with 1 coat of 1x pearl topcoat. Of course, that is 1/4 the amount of pearl topcoat that one would get with 2 coats of 2x pearl. So, I was very conservative (vs most) with the topcoat application.
Initially, I had a red push with my image. That was after calibrating my Panny AX100U projector. I later went into the individual color settings and was able to adjust the push out, and I that point felt that the image looked good at that point...at least to my eye.
Recently, some testing has been conducted on the pearl topcoat. So, we now have more data than we did when I painted my screen. The test consisted of taking two very neutral off-the-shelf grey paints (Winter Mist and Winter Mountain) and taking color readings on them. Those paints were then coated with 1 coat of 1x pearl (again, being frugle with the amount of topcoat...this is 1/4 of what is often recommended), using the Folkart pearlizing medium.
The results show that the color shift is significant. Th effect was similar on both Winter Mountain and Winter Mist. For those interested in the data, I'll use the Winter Mountain data as an example:
Here's a look at Winter Mountain without a topcoat:
Here's a look at Winter Mountain with one coat of 1x pearl:
For those interested in RGB numbers (I'm not personally a big RGB fan, as they can be misleading), the resulting values for Winter Mountain with 1 coat of 1x pearl topcoat were:
R,G,B = 209, 201, 195
Obviously, one can see that a red push is introduced with the addition of the pearl topcoat. Whether this can be compensated for using one's projector's calibration ability is going to vary on a case-by-case basis. In my case, I believe I was able to (or, at a minimum, I at least made it much better).
In this recent testing, no testing was done on 2 coats of 1x pearl, 1 coat of 2x pearl, or 2 coats of 2x pearl...so I won't speculate on what effect even more of the topcoat will have.
I'm not going to disseminate any advice one way or the other (as I don't want to engage in an argument)...I'm responding with this data only because it was mentioned that I used the topcoat and I wanted for everyone to have the same data that I now have. People considering DIY screen solutions should be given a chance to make the most informed decision possible...hence, this post.
Good luck with your screens...whatever you may decide!EDIT: See post below. The current recommendation, with Folkart Pearlizing Medium, is for 2 coats of 1x pearl, not 2 coats of 2x pearl. This is twice the amount of topcoat used on the test sample. So, the application that was tested is still conservative, but is not 1/4 of the topcoat used in the current recommendation (rather, it is 1/2).