silk screening ..... again..

[Brian Marshall]

Ok, ive done a little reading, and think i have this figured out... i did a lot of google searches, but most of the stuff that came up was about fabric.

Ok, as i understand it this is how it goes (or could go) for a simple design

1 make artwork
2 get a negative made on a transparency.

this is where it gets sort of hazy...

3 turn off the lights.  
4 lay emulsion on the screen.
5 place your tranparency on the screen.
6 shine a bright light on it until it dries....
7 rinse with water.
8 lay ink on the screen
9 place box under screen
10  use the roller to apply the ink
11 wait for it to dry
12 admire your work.

Brian

[Ansil]

Ok, ive done a little reading, and think i have this figured out... i did a lot of google searches, but most of the stuff that came up was about fabric.

Ok, as i understand it this is how it goes (or could go) for a simple design

1 make artwork
2 get a negative made on a transparency.

this is where it gets sort of hazy...
4 lay emulsion on the screen.

3 turn off the lights.

5 place your tranparency on the screen. >>>>>>  you can do this i found it better to lay it slightely above the screen as to keep it off of the emulsion
6 shine a bright light on it until it dries....
7 rinse with water.
8 lay ink on the screen
>>>do trial run on something the same size as your box.. ie a cardboard mock up of your box

9 place box under screen
10 use the roller to apply the ink >>>> rollor squeege potatoe tomato
11 wait for it to dry
12 admire your work.

Brian


yepp  bout it.

ansil

[Brian Marshall]

ok, it makes a lot more sense now....  woo hoo.

if i buy one of those starter kits will those be ok???  I know the ink will suck.

Also, can i reuse the screen.... take all the emulsion off, and re do it?

[Ansil]

yep but it is a bitch...

[Paul Perry (Frostwave)]

Cleaning the emulsion off the screen is something that you want to do sooner rather than later, because it gets more hardened as time goes on.
An alternative to the 'painted on' emulsion is a sheet of emulsion tht is kept in a light tight container rolled up & you moisten it & stick it to the screen (I think this is true.. it is all many years ago).
Certainly the painted on emulsion wd be cheaper. There are also special chemicals for cleaning the screen but I have no idea whether it is worth it.

[bobbletrox]

Ok, as i understand it this is how it goes (or could go) for a simple design

Not quite!

3. turn off fluro lights and work in low-light to coat the screen w/t emulsion.  I find doing this at night the best -with just a dim table lamp on.

You can buy these handy dealies (see pic) that let you apply a nice even and thin coat of emulsion to the screen.  It's basically just a metal trough that you pour some emulsion into and draw it against the screen at an angle (see pic).  Usually one coat on each side does the trick, but you can experiment with two on the print side and one on the squeegee side -or vise versa.

http://users.bigpond.net.au/styrowfoam/SCREENIE.jpg">

4.  put the coated screen inside a dark cupboard on a level surface, and put some blocks under the edges so it sits elevated with the print side down.  Leave it overnight to "dry".

5.  When you come back in the morning, the emulsion should be nice and smooth and tacky to the touch.  Get your artwork (which is on a transparency) and place it on the print side of the screen.  Cover it with a piece of glass to make sure no light leaks under your design.  This way you'll get nice crisp edges!

6.  Grab a watch or clock or timer and scoot outside and place your screen/artwork/glass sandwich in direct sunlight -I find the noon sun to be best.  Start your timer and expose your screen for about 45 seconds.

7.  Take the glass and artwork off and run into a laundery or grab a hose and run water over the screen to knock the emulsion out of your design.  Lukewarm water under mild pressure works best, and you can gently massage the screen to encourage the unexposed emulsion out of your design.  Remember to do this part out of direct sunlight -do it in the shade or indoors.

8.  You'll gradually see the emulsion where your design is wash away.  Inspect the screen to make sure it's lookin' good.  If the emulsion isn't washing out -it was exposed for to long.  If all the emulsion is washing off your screen -it needed to be exposed for longer.  You can dab a bit of emulsion onto the print side to fix up any minor defects if the main part of your design still came out ok.  Once you're happy with your screen you can stick it in the sun to dry.

9.  Squeegee away!

IF YOUR SCREEN SCREWED UP (and it probably will the 1st time):
*  You can reclaim the screen by washing the emulsion out with screen reclaimer...available at printing supply stores.
*  The Cheaper Way;  Just make your own screens by making a frame out of cheap timber and buy some screen mesh.  That way you can just rip out a bad screen and stretch a new screen on the frame using a staple gun.  There are a few tutorials detailing how to stretch your own screens on the internet.

The exposure times vary for different emulsions, so experiment.  The sun is a FAR FAR FAR better way to expose screens than using UV lamps.  The sun is the biggest UV lamp in the solar system!   And it's free!

I hope this helps.

[Ansil]

WHAT emulsion are you using that you have to let it dry overnight.

the stuff i got you can't do that.  

must be different than mine, cause 45seconds isn't nearly long enough to expose what i got, maybe thats why we used a projection system. as it takes aprox 15-20 minutes to do one screen

[bobbletrox]

Think of it this way;  the sun acts like 50 billion bulbs working at once.  That's why it's so much faster.  I know of a printing factory that uses sunlight to expose their screens on all but overcast days because it costs too much to run a UV bulb strong enough to do it in as little time every day.

Oh...and the emulsion doesn't really "dry" per se.  It just goes tacky so you can put the artwork directly on top of it safely.  It can still be washed out at this stage.  It's not until you expose it with the artwork on top that the unexposed areas wash out and the exposed areas remain.

The emulsion I use is Kiwocol brand.  It comes with a bottle of sensitiser you've gotta mix in to activate it.

[sfr]

2 get a negative made on a transparency.

It doesn't actually have to be a "negative" per se - basically, you want the transparency to be black where the ink is going - so if you were printing with white ink, it wouldn't really be a "negative" - maybe I've just made it confusing, but basically - transparency is black where ink will go.

Make sure the transparency is as dark as you can get it - if it's a photocopy, you want the toner good and dark, to make sure no light bleeds through.  Some people lay two transparencies, one on top of the other to make sure.  I find this is too much of hassle, making sure things register right, but I tend to some pretty fine line designs as well.

this is where it gets sort of hazy...

3 turn off the lights.  

Most emulsions you've got a little lee-way, you can lay the emulsion on in normal room-light, as long as it doesn't take too long.

4 lay emulsion on the screen.

Make sure you get an even coat of emulsion.  You don't need to worry about getting all the way to the edges of the screen, you can mask that, but make sure you get emulsion over enough area to cover yr design, and that it's thick enough to plug up all the weave of the fabric in the screen.  

5 place your tranparency on the screen.

Actually, you want to make sure you let the emulsion dry first!  Put the screen in a dark area.  (I usually put it under a box or in my closet)  Depending on how "goopy" or "runny" (yes, those are technical terms  )  the emulsion is, it may drip.  (So if you leave it in a dark room, make sure it's over some newspaper, not the carpet!)  I usually lay the screen horizontal, with the side that I did the last pull with the squeegee when spreading the emulsion, with that side down.  (So the side with a little more emulsion coating it is on top, and it will drip through the screen and cling, and not drip off the screen).  Leave it in the dark area until the screen is entirely dry!  transparencies stick to wet emulsion and it's a pain.  I usually set up a small fan blowing across the screen, this helps it dry quicker, and drying quicker helps the emulsion from dripping if you applied a lot of it or it's runny.  


At this point, you go on to your step 5 -  Contrary to what Ansil says, I find it best to get the transparency as firmly against the screen as you can - if the emulsion is dry, everything should be fine.  If you're doing real fine line details, you need the transparency to be right against the screen so light won't "bleed" under and wash out the lines.  Some people tape the transparency to the screen, I usually lay a heavy piece of glass over it.  You usually have to stick it on there somehow, because often times the heat from yr exposing lightbulb will make the plastic transparency curl.


6 shine a bright light on it until it dries....

The emulsion should already be dry at this point, just not exposed. (Dry is the emulsion chemical is no longer tacky, just like how you'd imagine paint - exposed means it's been hardened on by the light)
The light needs to be very bright - I use a photoflood bulb, like what they have at the picture studio something like 200 watts, inside of a metal reflector with a clip that I got at a hardware store.  Some people use halogen lights shoplights, you can get away with a 150 watt bulb in tin.  If you want to be hardcore about it, you can buy or make an exposing table, which would be a bunch of tube lights with a piece of glass over it that you'd lay the whole thing on.

Like I said, though - I use a 200 watt photobulb, and a reflector, and shine it on the screen from about 12 inches up.  It helps to have some black paper behind the screen, especially if you didn't coat it all the way to the edges, to keep light from reflecting back up from under the screen.  

There are two things that will expose the photoemulsion at this point - light, and heat - light is the obvious one, and what we're going for - it can only expose the emulsion where it can hit it - i.e., anywhere the transparency isn't blocking it.  (as a side note, instead of a transparency, you can use a stencil or cut out or whatever - if you just wanted to do letters, you could simply use sticky letters right on the emulsion - anything that will block light, basically.)  Heat is a sort of harder to control one - and unlike light, it can obviously expose yr screen through yr transparency.  It's usually not an issue - but you want to be careful, particularly if you're using a high powered light bulb to expose the screen - it gets hot under those things.  I do two things - one, I set up a fan to blow across the screen (this is another reason laying glass over transparency helps, besides just keeping it firmly against the screen!)  And I move the light a bit or angle it slightly different every 5 to ten minutes or so - it generally just gets hot directly undereath the center of the bulb.  If you have a large screen or the light from your bulb isn't diffused enough, this also helps to make sure all parts get exposed enough.  

If you keep heat from getting to the screen,  (this isn't usually a problem with the tube bulbs in exposing tables, another benefit besides the shorter exposing time you get from being able to get the light right on the screen) and yr transparency is opaque enough, you generally can't over-expose the screen, although very fine lines may bleed over.  In general it's good practice to only expose it as much as need be though.  With a 150 watt bulb, it's usually like a half-hour with the light 12-inches away.  It kind of varies and depends on yr setup.  Most emulsions give a time chart, go by that.  Something I do is set a coin on an unused area of screen - you don't want to move the transparency until it's done exposing, but you can slide the coin if you want to - as the emulsion exposes, you can sort of see the colour difference between the exposed emulsion around the coin, and the unexposed emulsion under the coin.  Of course, this only helps when you've done a few screens with your brand emulsion and know what the colour difference should look like.  It's not as drastic as you'd think.

7 rinse with water.

Make sure it's COLD water.  As cold as you can get from yr tap.  If you have a sprayer nozzle on yr sink, this will help alot, otherwise, you may have to get in the shower.  It might take a while to get the emulsion out - don't worry.  Rinse both sides.  You should start seeing a colour change in the exposed emulsion almost immediatly, at least with the brands I use, it starts to get much darker.  The unexposed emulsion gets a bit lighter.  After rinsing for a while, (both sides!) the unexposed emulsion will start to peel off and leave the screen.  At this point, I usually take the sprayer push it right against the screen.  You can scrub at the screen gently with the sprayer or your fingers or even a soft tooth brush (I suggest using your roomate's, but you might not want to let them know of this fact [just kidding]) to get the stuff out if it's not coming, but usually a strong spray of cold water should be enough.  It'll be splashing all over.


At this point, the emulsion is probably kind of tacky again, and the screen is wet as all get out - you can blowdry it, or wave it in the air outside, or just let it air dry, but you should let it dry before making prints.  I usually just make my prints the next day.

8 lay ink on the screen
9 place box under screen
10  use the roller to apply the ink
11 wait for it to dry
12 admire your work.

Printing -

 I like my ink pretty thick - it should at least not be runny.  Make sure it's stirred real well.  Nicer inks are usually pretty consistent, some cheaper inks are kind of hit or miss and you may need to leave the pot open for a day to thicken up, or add some water (not much!) to thin.  I guess it should be pretty creamy, pasty.  kind of like sour cream, I guess?

If you didn't go all the way to the sides of the screen, now's the time to mask those areas off.  Same thing if yr screen has a spot in it somewhere from my coin trick above, or a major hole somewhere you didn't mean to be there.  If you made more than on design on a screen and you want to print  just one, mask that.  If you want to print part of your design in one colour, and part in another, mask those areas you don't want printed now.  (For more complex designs, you generally use more than one screen, but for something simple you can use one screen twice, masking different parts.)  

To mask the screen, you can just use masking tape.  If it's an area you want more permanently covered, duct tape is okay, I find.  Stick it on the bottom of the screen, make sure it's firm against the screen, and relatively flat.  

Lay a bead of ink across the top of the screen, a little bit wider than your design.  It's almost always better to use extra ink and scrape it off later than not have enough.  

Most people do what's a flood fill first - taking your squeegee (I've never heard of anyone screen printing with a roller, by the way - you want a squeegee, but even a firm piece of cardboard could work.  Screen printing squeegees are firmer than the kind you use on yr winshield, although I have used one of those in a pinch) Anyway, the flood fill - take your squeegee, and with almost no pressure at all, pull some ink across the screen, (w/o the screen actually touching anything underneath, i.e. - yr not printing yet!) This gets the screen lightly covered in ink so that making prints is easier.  You don't want really hardly any pressure here at all, otherwise all sorts of ink will go through the screen, this is just sort of to float the ink across the top of the screen.

lay your screen firmly on top of what you want to print.  if you're printing a raised surface smaller than the size of your screen, (like a stompbox!) you want some sort of jig to hold the screen at the appropriate height.  (if you make a lot of prints, a hinged jig is a great idea anyway) With a firm pressure, pull the squeegee across the screen, forcing ink through the open parts of the screen.  You might need a couple of pulls - if you look at the screen, you'll sort of be able to tell where the ink has pushed through, you can see the fibers of the screen again.  (I don't know how to explain this, it's sort of a colour change, it'll make sense when you do it)  
Make sure that you don't slide the screen around at all during this process, or you'll get a blurry print.  Lift up the screen (and here's where a hinged jig helps) in one clean motion.  Stompboxes are nice to print, because unlike t-shirts and posters, they don't realy try to stick to screen, so it's pretty easy to lift off w/o smearing the design.  

It's usually a good idea to make a few test runs on scrap paper or cardboard to get a good idea of how the printing process goes before you commit to whatever you're doing, but depending on yr ink, it should be fairly easy to clean off a stompbox while still wet if you really screw up.

As soon as yr done printing, make sure you clean the ink out of yr screen with cool water!   This is the same as cleaning the emulsion out when you exposed the screen, but it's easier and you can scrub at it a little bit if you need to.  Some people even just soak their screens for a bit when they're done.  You don't want to the ink to dry in the screen - it can be a real pain to get out, especially with some types of inks, and you can lose the fine line detail in yr screen.  I usually use a spatuala to try and get all the extra ink of the screen and back into the bucket that I can.


As far as reclaiming a screen (that's what you call it when you take the emulsion off to re-use the screen) it is possible, but like Ansil said, it's a pain in the ass.  It really depends on the type of emulsion you're using.  Sometimes, removing the emulsion can be a bit damaging to the silk and you can only do it so many times.  I generally don't reclaim my screens alll the time, but it is doable.

I would suggest either getting one of the speedball starter kits at an art store, or a package of Speedball emulsion (they mostly sell the Speedball "Hunt Diazo" type now, the other Speedball kind has been discontinued - but hte Diazo stuff is nice, after you coat a screen, you can wait a few days to expose it if you keep it dark and cool.  (I used to keep mine in the fridge!) The other Speedball emulsion (not the Diazo kind) I know you could mix just a bit a time - the Diazo stuff tells you too mix the entire two bottles up to make all the emulsion, (emulsions comes as two chemicals, the emulsion itself, and the "sensitizer" that makes it sensitive to light) but I have a feeling if you kept the ratios right, you could mix it up in smaller batches.  

But yeah, I'd either get a starter kit, or get a pre-made screen, (you can make yr own, but you want them to be tight as a drum!) squeegee, and bottle of emulsion, and then get high-powered light bulb at a hardware store or photo place and some sort of reflector.  If you don't live near a place with all this stuff, you can get it online at www.dickblick.com.  They also sell professional inks there.  (Which is really the only professional stuff I'd buy for at-home screen printing, the Speedball home stuff is fine for everything else. However, I've seen people screenprint with housepaint and oil paint and all sorts of stuff, so go wild!)

wow - I just typed a bit more than I thought.  I should probably go back and proofread it, but I really need to get to bed, I just worked a 12-hour night shift.

Anymore questions, ask away.  And if anyone lives near Burlington, Vermont, I'll be more than happy to walk them through the screen-printing process.  I've been doing shirts and posters in my home for a while now, with my whole rig and everything 100% DIY.  One of the few things I'm pretty good at.  (I'm getting there with the pedals though )   Maybe I should make a video or something.


[/i]

[sfr]

bobbletrox beat me too it - I type too slow after work  

I don't know any emulsions that *need* to dry overnight, but if you keep it dark and cool, it doesn't matter.

the real professional emulsions tend to expose quicker than, like, Speedball stuff, although I've never been able to get a screen to expose in the sun.  But it all depends on what type yr using.  Some are very sensitive to the UV.

Another option, similar to what Pete described, is rather than doing all the emulsion junk, getting a roll, but it's actually a sort of stencil stuff that you cut into and then stick on.  I think this is technically called "gocco" or something?  I've never used it.

The trough thing bobbletrox talked about helps alot for coating the emulsion not to thick.

I make my own screens similar to the screen printing frames you see in the art store, by routing an 1/8th groove in the wood to hold the silk in with a piece of cording.  I stretch the silk out kind of firmly, and then push it into the groove with the cording and a tool for applying screen door screen, actually, this holds it in firmly.

[ErikMiller]

if i buy one of those starter kits will those be ok???  I know the ink will suck.

I'd definitely get different ink. The kits are oriented toward t-shirts and crafts kinds of things.

I dunno. The kits I saw were going for $75, which is $25 more than I paid to have a professional shop make me a screen with an aluminum frame, and that also included a squeegee.

Unless you're dedicated to doing it yourself (cost effectiveness is indeed a lower priority in our hobby) you might get a quote from a screen shop before you go much further.

Me, I get enough jollies with making the rest of the pedal.

[Brian Marshall]

if i buy one of those starter kits will those be ok???  I know the ink will suck.

I'd definitely get different ink. The kits are oriented toward t-shirts and crafts kinds of things.

I dunno. The kits I saw were going for $75, which is $25 more than I paid to have a professional shop make me a screen with an aluminum frame, and that also included a squeegee.

Unless you're dedicated to doing it yourself (cost effectiveness is indeed a lower priority in our hobby) you might get a quote from a screen shop before you go much further.

Me, I get enough jollies with making the rest of the pedal.

if i plan on making a few different ones then all i have to buy is the screen later on.  There is a guy that is interested in selling one of my designs, but my stuff just doesnt look good enough.

I just made a box with a decal, and it looks sort of hoakey.  I have a big problem with dust in my garage while i'm painting.  I think i am going to build a box for painting that closes after i'm done spraying.  I got a bunch of crap under my decal and it looks bad.

Brian

[Brian Marshall]

if i buy one of those starter kits will those be ok???  I know the ink will suck.

I'd definitely get different ink. The kits are oriented toward t-shirts and crafts kinds of things.

I dunno. The kits I saw were going for $75, which is $25 more than I paid to have a professional shop make me a screen with an aluminum frame, and that also included a squeegee.

Unless you're dedicated to doing it yourself (cost effectiveness is indeed a lower priority in our hobby) you might get a quote from a screen shop before you go much further.

Me, I get enough jollies with making the rest of the pedal.

if i plan on making a few different ones then all i have to buy is the screen later on.  There is a guy that is interested in selling one of my designs, but my stuff just doesnt look good enough.

I just made a box with a decal, and it looks sort of hoakey.  I have a big problem with dust in my garage while i'm painting.  I think i am going to build a box for painting that closes after i'm done spraying.  I got a bunch of crap under my decal and it looks bad.

Brian

[ExpAnonColin]

Man, it is just me, or does this seem like more work than it's worth?

-Colin

[bobbletrox]

Man, it is just me, or does this seem like more work than it's worth?

bingo.  :wink:

[Brian Marshall]

Man, it is just me, or does this seem like more work than it's worth?

-Colin

Hey i've seen your work... I am half tempted to send all my stuff to you and have you paint everything with latex paint and a paint roller.  Then you can label it with a white paint pen.  Then 2 months later when it dries you can ship them back to me...  I'll pay you $.02 each.

We could call it... 'colin's custom edition' or something...  i dunno...  

But seriously,  this is just like cars... some people just want to get their 1983 datsun 210 running like a BMW, and others just want to make it look like one... The people who are better off are probably somewhere in between.

Brian

[ErikMiller]

If you plan to make and sell at least 10 of the same pedal, getting a screen made is the way to go.

Making the screen yourself seems kinda hair shirt to me, but I can understand wanting to learn the skillz.

But for one-off's, I'm happy with decals. For my own use, I'm down with Dymo tape. I see such units as prototypes.

[sfr]

Coming as a guy who makes screens to make just one shirt for himself, I'm all for it, but I'm also a little bit nuts.  (My therapist says I'm doing better, though )   In general, yeah, screening is usually only worth the effort for more than one pedal.

Something that could be interesting would be to have a standard screen for all your pedals, and you just added in the knob names, maybe  a pedal name,  with decals, so they all have a uniform look.  You could maybe do everything in white ink, with little white fields where you could pen in the knob names carefully or something.

I can't stand Dymo tape.  (That's the plastic raised letter stuff, right? Or do you mean the newer computer-made stuff?)  But I'm a little biased - when my first band in high-school self-released a 7" record, we thought we'd save money on labels by just getting plain black labels on the record.  Well, I found a dozen rolls of Dymo tape at a garage sale, so we labelled all the records with that.  Well, lets say that 300 records worth of yr band name and EP name of "turn-and-click, turn-and-click" will drive you nuts.  Seeing a labelmaker still makes my thumbs hurt . . .

I don't know why I ramble on so much. . .    

[Paul Perry (Frostwave)]

It is really easy to temporarily block out sections of a screen, so if you are ingenious you could make a single screen that would do for a number of boxes.
And (in case anyone doesn't already know) just about every commercial PCB starts with silk screening the resisting layer onto the raw copper coated board...