P'n'P blue vs photo boards

[freak scene]

what are the pros and cons of both, i am ready to make the jump from drawing on copper with a sharpie, and i just about paid off one of my credit cards

[freak scene]

bumphomet

[mydementia]

Do a search here - lots of threads on the subject.

Here's my 2-cents:
I started out using photo paper and had very inconsistent results.  I hated scrubbing off the paper after ironing and never quite got it all off...maybe I never found the right kind of paper...folks using that method say to use inkjet paper in a laser printer - I never found a print shop that would do it...and I didn't want to gum up my work printer (it has enough trouble).  I tried several different laser photo papers - all with varying degrees of the same poor results. 

...then there's PNP Blue...
I bought a few sheets from Steve (at smallbearelec.com) with my last order - wow...like night and day.  Now that I have the ironing technique down (threads on this too) I get VERY good results - I've even been able to etch intricate 2-point font!  ...and have you seen what markm has been doing on enclosures?  This is definitely the way to go.  Just be sure to buy at least 5 sheets because you're going to 'lose' one to the learning curve!
Have fun.
Mike

MODIFIED: Just noticed you were asking about photo-sensitive boards... I almost used this approach several times - just seems like more chemicals and more processing...instead of an iron, you use light...it does allow you to print with whatever printer you want on transparency film though...

[freak scene]

MODIFIED: Just noticed you were asking about photo-sensitive boards... I almost used this approach several times - just seems like more chemicals and more processing...instead of an iron, you use light...it does allow you to print with whatever printer you want on transparency film though...

yeah i have searched but there didnt seem to be very many posts about the photo sesitive boards.  tons about P'n'P though.  i am leaning that way anywho, less chemicals.

[The Tone God]

Photo is a more "professional" method. Upsides are that they can produce cleaner, more consistent, and more accurate boards. The downsides are time, more chemicals, more cost, and more labour and skill needed.

Andrew

[Mark Hammer]

In terms of resolution and capacity to handle thin/close traces without creating copper birdges between traces, the methods are ranked (best to worst): photo, PnP, photo paper, Sharpie.

There are a surprisingly large number of PCB layouts that are comfortably made using the Sharpie method.  When the parts count is below 30 or so the Sharpie-based layout can often still easily fit inside a 1590B.  It's obviously more work than transfer techniques, but the resolution is more than acceptable if not beautiful to look at.

What one uses PnP vs glossy photo paper for depends on the layout and the need for crisp clean lines.  The resolution and cleanliness of those lines will depend on the particle size of the backing and the emulsion covering.  Photo paper emulsion breaks off from the backing in bigger particles than the blue layer does on PnP.  I have to say I've successfully made plenty of fairly tightly packed boards using photo paper, but there are plenty of things I would not want to try with photo paper because the resolution demands are too high.  If the traces pass between pads of an IC, then photo paper is off limits for me.  Same thing if there are more than 3 traces running up the middle of an IC (i.e., between the two columns of pads for the IC pins).

Photo-sensitive boards are what you use for very high-density circuits.  You can certainly use it for making stuff as simple as a Bazz Fuss, but you don't need to.  If the board uses SMT components, then photo-sensitive process would be more useful, but otherwise PnP is often more than sufficient and certainly involves less cost and difficulty/steps.