Newbie printer...thin line of emulsion after exposure and cleaning/reclaiming...
So I just started out printing on paper (well printing in general) and first off...I should have done my research before spending upwards of $200 on speedball products...it's what I used as a teen (all I had available) and when deciding I had some time and money to burn it's what I went to thinking it was the standard...now I see pretty much everyone hates on the stuff...oh well, once it's gone I'll start replacing with proper materials Buuuut, on to my question.
I have a 10x14" screen i developed under a 500w light at 16" for 18 minutes and used a smaller piece of glass from a cheap photo frame to hold my film positive down, all worked great, the image burned as planned except for a small very thin line around the glass also blocked the light. I thought eh what the hell, covered it with screen filler fluid and went on printing my christmas cards...which turned out pretty awesome (albeit a little warholish due to learners mistakes in registration hahahaha...I'm going to say it's artistic uniqueness hahaha). Finished printing, cleaned my ink, applied my speedball emulsion remover and all came out nicely except for the hairline that the glass blocked. I ran some speedball speedcleaner over it...no luck. More emulsion remover, still nothing.
There is also one other spot of fine detail where the ink or emulsion seems to have gotten stuck (its in the actual print area, in an area of ghosting)...is this screen lost or can I somehow get it clean? I do not have a power washer and pretty much do all my cleaning in the kitchen sink...
I hate that screen filler / screen drawing stuff. You can just spread old emulsion over the line to fill in gaps like that. No need for two different products. Also, the filler doesn't always work with the emulsion remover; different ingredients.
Try setting up a rig where the glass is larger than the screens you're exposing, and it's a non-issue.
Ohh, if I had a larger piece of glass or plexi, that means I'd have to flip the screen over and develop it printing side up? Ive always done it the other way, printing side down, on the black paper, the film positive on the top (ink? side) and glass on top...nice flat good contact....i was just going to the hardware store to pickup a piece of plexi 1/4 smaller than the inside diameter of the frame...whats the benefit to developing the other way around?
What I'm used to seeing is like this, from bottom to top:
-screen (print side down)
-padding or something to hold the mesh flush with the positive
-lid or stack of books or whatever
You can change it around a bit, but the stupid thing about having the light free floating is that changing the distance between light and screen will also change exposure times and results.
There are a lot of ways to go, and you can even try using a space bag (vacuum seal storage bag) to keep contact consistent. Eventually, it's just good to have the consistency of a static, all-parts-locked-down exposure unit in order to streamline the process.
When you move past the speedball level stuff/crude printing, and once you start trying to do extreme fine detail/halftones etc, you'll find exposing from the front side will not give you good detail. the reason is you are not exposing emulsion to emulsion. And just to be clear, speedball inks are great for starting out and general printing. It's their screens/emulsion/squeegees and some methods that are a little shakey.
The film has the image on one side. this side should be against the emulsion on the mesh. Unless you make your image flopped or flipped, you have to do it with the film against the bottom (stock side) of the screen.
If you don't have emulsion to emulsion and intimate contact, your fine lines and dots and really any image close in as the light can angle under the image through the thickness of the film.
if you are using a point light, it's no problem to expose. From the bottom up: foam pad inside frame but thicker than frame, screen with bottom up, image film face down, glass. Set your lamp height at 1.5 times the diagonal and use the same height for each exposure and you are good.
Blocking out an edge opening like you describe, you can use tape on the top (I use clear packing tape). Seal it down with your fingernail before starting to print and it should resist lifting from the ink. if you want to block out, like Vroom says, use emulsion. Put it on thin, let it dry, expose it to the sun or your lamp.
A power washer is a must especially after you give up on speedball emulsion. I also just use packing tape to block imperfections like the edge of the glass. I also don't hate speedball ink. If I printed with a higher volume I'd make the leap into TW but for the amount of printing I do it just makes the most sense for me to stick to speedball. I actually really like most of it, but some dark colors scuff very easily.
While I agree a power washer is a must, I suggest a 1600 psi or less, which can run about 70 bucks at walmart. Taking a small hobbyist screen to a car wash could ruin a cheap homemade/speedball screen depending on how strong the washer is.