I begin to wonder now what is going on.
When I make circuits, I use a presensitized PCB board from MG chemicals along with their positive developer (sodium hydroxide?)
This is my 2nd attempt of a circuit I attempted to develop (I'm reusing the mask that was printed with toner on vellum paper rated at 105gsm).
On the first attempt, the circuit background turned pure copper which is good but some tracks faded away.
Now the second attempt got worse even though I taken advice.
One advice I took (I believe from kinsten, a chinese PCB supplier) was to move the UV light for exposure to 4 to 6 cm away from the board and expose for a shorter time. For both tests I used roughly a 20 minute exposure time.
For my developer mix, I used about 12 parts of water to 1 part of developer which is weaker than what MG chemicals suggested, and I deliberately did weaker to see the action.
I then shut my room light off and the brightness in my room was at about 10% since outside was dusk. It was still hard to see fine print without light shining on it.
Once I shut my light off, I go and use an ultra-bright red LED as my safelight when handling and developing the PCB since the presensitized PCB is sensitive to light.
I then sandwiched the circuit board and the artwork together (toner side to the circuit board)
After exposure, I briefly examined the board and noticed the pattern. Then I put my board in developer for about two minutes. Once I'm done, I rinsed it and thought my circuit is perfect, but once I turn the normal light back on, I was dismayed to see that part of the circuit board background was faint green, but what's worse is that one track was fading away into the background, yet my original artwork didn't call for this.
What could I be doing wrong? Could the vellum be the culprit? am I forced to just use transparencies? I've wasted at least $20 to unintentionally make failing boards and I don't want to make anymore.
Someone suggested using sodium silicate instead of sodium hydroxide but I think there's more to it.
Any ideas?
UPDATE
As requested by someone, I needed to mention in my question that I don't have a good quality camera to take the pictures with.
The track size thats problematic is 0.3mm wide.
The UV source is this cfl-like light: spencers.scene7.com/is/image/Spencers/00912691-a?$Thumbnail$